Accessing data in multiple dispersed storage networks

ABSTRACT

A method begins by a processing module identifying sets of dispersed storage (DS) units for each of a plurality of dispersed storage networks (DSNs) in a computing system network, wherein a set of the sets of DS unit stores an error coded data file. The method continues with the processing module identifying a reference entity within the computing system network. The method continues with the processing module determining first data access performance information between the reference entity and a first one of the sets of DS units and determining second data access performance information between the reference entity and a second one of the sets of DS units for each of the plurality of DSNs. The method continues with the processing module storing the first and second data access performance information for each of the plurality of DSNs to produce system data access performance information.

CROSS REFERENCE TO RELATED PATENTS

This patent application is claiming priority under 35 USC §119 to aprovisionally filed patent application entitled INTER-DISPERSED STORAGENETWORK COMMUNICATIONS having a provisional filing date of May 19, 2010,and a provisional Ser. No. 61/346,203, which is hereby incorporatedherein by reference in its entirety and made part of the present U.S.Utility Patent Application for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates generally to computing systems and moreparticularly to data storage solutions within such computing systems.

2. Description of Related Art

Computers are known to communicate, process, and store data. Suchcomputers range from wireless smart phones to data centers that supportmillions of web searches, stock trades, or on-line purchases every day.In general, a computing system generates data and/or manipulates datafrom one form into another. For instance, an image sensor of thecomputing system generates raw picture data and, using an imagecompression program (e.g., JPEG, MPEG, etc.), the computing systemmanipulates the raw picture data into a standardized compressed image.

With continued advances in processing speed and communication speed,computers are capable of processing real time multimedia data forapplications ranging from simple voice communications to streaming highdefinition video. As such, general-purpose information appliances arereplacing purpose-built communications devices (e.g., a telephone). Forexample, smart phones can support telephony communications but they arealso capable of text messaging and accessing the internet to performfunctions including email, web browsing, remote applications access, andmedia communications (e.g., telephony voice, image transfer, musicfiles, video files, real time video streaming. etc.).

Each type of computer is constructed and operates in accordance with oneor more communication, processing, and storage standards. As a result ofstandardization and with advances in technology, more and moreinformation content is being converted into digital formats. Forexample, more digital cameras are now being sold than film cameras, thusproducing more digital pictures. As another example, web-basedprogramming is becoming an alternative to over the air televisionbroadcasts and/or cable broadcasts. As further examples, papers, books,video entertainment, home video, etc. are now being stored digitally,which increases the demand on the storage function of computers.

A typical computer storage system includes one or more memory devicesaligned with the needs of the various operational aspects of thecomputer's processing and communication functions. Generally, theimmediacy of access dictates what type of memory device is used. Forexample, random access memory (RAM) memory can be accessed in any randomorder with a constant response time, thus it is typically used for cachememory and main memory. By contrast, memory device technologies thatrequire physical movement such as magnetic disks, tapes, and opticaldiscs, have a variable response time as the physical movement can takelonger than the data transfer, thus they are typically used forsecondary memory (e.g., hard drive, backup memory, etc.).

A computer's storage system will be compliant with one or more computerstorage standards that include, but are not limited to, network filesystem (NFS), flash file system (FFS), disk file system (DFS), smallcomputer system interface (SCSI), internet small computer systeminterface (iSCSI), file transfer protocol (FTP), and web-baseddistributed authoring and versioning (WebDAV). These standards specifythe data storage format (e.g., files, data objects, data blocks,directories, etc.) and interfacing between the computer's processingfunction and its storage system, which is a primary function of thecomputer's memory controller.

Despite the standardization of the computer and its storage system,memory devices fail; especially commercial grade memory devices thatutilize technologies incorporating physical movement (e.g., a discdrive). For example, it is fairly common for a disc drive to routinelysuffer from bit level corruption and to completely fail after threeyears of use. One solution is to a higher-grade disc drive, which addssignificant cost to a computer.

Another solution is to utilize multiple levels of redundant disc drivesto replicate the data into two or more copies. One such redundant driveapproach is called redundant array of independent discs (RAID). In aRAID device, a RAID controller adds parity data to the original databefore storing it across the array. The parity data is calculated fromthe original data such that the failure of a disc will not result in theloss of the original data. For example, RAID 5 uses three discs toprotect data from the failure of a single disc. The parity data, andassociated redundancy overhead data, reduces the storage capacity ofthree independent discs by one third (e.g., n−1=capacity). RAID 6 canrecover from a loss of two discs and requires a minimum of four discswith a storage capacity of n−2.

While RAID addresses the memory device failure issue, it is not withoutits own failures issues that affect its effectiveness, efficiency andsecurity. For instance, as more discs are added to the array, theprobability of a disc failure increases, which increases the demand formaintenance. For example, when a disc fails, it needs to be manuallyreplaced before another disc fails and the data stored in the RAIDdevice is lost. To reduce the risk of data loss, data on a RAID deviceis typically copied on to one or more other RAID devices. While thisaddresses the loss of data issue, it raises a security issue sincemultiple copies of data are available, which increases the chances ofunauthorized access. Further, as the amount of data being stored grows,the overhead of RAID devices becomes a non-trivial efficiency issue.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of a computingsystem in accordance with the invention;

FIG. 2 is a schematic block diagram of an embodiment of a computing corein accordance with the invention;

FIG. 3 is a schematic block diagram of an embodiment of a distributedstorage processing unit in accordance with the invention;

FIG. 4 is a schematic block diagram of an embodiment of a grid module inaccordance with the invention;

FIG. 5 is a diagram of an example embodiment of error coded data slicecreation in accordance with the invention;

FIG. 6 is a schematic block diagram of another embodiment of a computingsystem in accordance with the invention;

FIG. 7 is a flowchart illustrating an example of storing data inaccordance with the invention;

FIG. 8 A is a flowchart illustrating another example of storing data inaccordance with the invention;

FIG. 8 B is a flowchart illustrating an example of authorizing encodeddata slice storage in accordance with the invention;

FIG. 9 is a flowchart illustrating an example of retrieving data inaccordance with the invention;

FIG. 10 is a flowchart illustrating an example of rebuilding data inaccordance with the invention;

FIG. 11 A is a flowchart illustrating an example of publishing storageinformation in accordance with the invention;

FIG. 11 B is a flowchart illustrating another example of accessing datain accordance with the invention;

FIG. 12 is a flowchart illustrating an example of migrating data inaccordance with the invention;

FIG. 13 is a flowchart illustrating an example of modifying the storageof data in accordance with the invention;

FIG. 14 A is a flowchart illustrating an example of generating billinginformation in accordance with the invention;

FIG. 14 B is a flowchart illustrating an example of aggregatingdispersed storage network (DSN) usage information in accordance with theinvention;

FIG. 15 A is a flowchart illustrating another example of storing data inaccordance with the invention;

FIG. 15 B is a flowchart illustrating another example of retrieving datain accordance with the invention;

FIG. 16 A is a flowchart illustrating an example of assigning a newvault in accordance with the invention;

FIG. 16 B is a flowchart illustrating another example of assigning a newvault in accordance with the invention;

FIG. 16 C is a flowchart illustrating an example of accessing adispersed storage network in accordance with the invention;

FIG. 17 A is a flowchart illustrating an example of acquiring securityinformation in accordance with the invention;

FIG. 17 B is a flowchart illustrating an example of assigning securityinformation in accordance with the invention;

FIG. 18 A is a flowchart illustrating another example of acquiringsecurity information in accordance with invention;

FIG. 18 B is a flowchart illustrating another example of assigningsecurity information in accordance with the invention;

FIG. 19 A is a flowchart illustrating an example of requesting access toa dispersed storage network (DSN) in accordance with the invention; and

FIG. 19 B is a flowchart illustrating an example of processing adispersed storage network (DSN) access request in accordance with theinvention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of a computing system 10 thatincludes one or more of a first type of user devices 12, one or more ofa second type of user devices 14, at least one distributed storage (DS)processing unit 16, at least one DS managing unit 18, at least onestorage integrity processing unit 20, and a distributed storage network(DSN) memory 22 coupled via a network 24. The network 24 may include oneor more wireless and/or wire lined communication systems; one or moreprivate intranet systems and/or public internet systems; and/or one ormore local area networks (LAN) and/or wide area networks (WAN).

The DSN memory 22 includes a plurality of distributed storage (DS) units36 for storing data of the system. Each of the DS units 36 includes aprocessing module and memory and may be located at a geographicallydifferent site than the other DS units (e.g., one in Chicago, one inMilwaukee, etc.). The processing module may be a single processingdevice or a plurality of processing devices. Such a processing devicemay be a microprocessor, micro-controller, digital signal processor,microcomputer, central processing unit, field programmable gate array,programmable logic device, state machine, logic circuitry, analogcircuitry, digital circuitry, and/or any device that manipulates signals(analog and/or digital) based on hard coding of the circuitry and/oroperational instructions. The processing module may have an associatedmemory and/or memory element, which may be a single memory device, aplurality of memory devices, and/or embedded circuitry of the processingmodule. Such a memory device may be a read-only memory, random accessmemory, volatile memory, non-volatile memory, static memory, dynamicmemory, flash memory, cache memory, and/or any device that storesdigital information. Note that if the processing module includes morethan one processing device, the processing devices may be centrallylocated (e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that when the processing module implements one or more ofits functions via a state machine, analog circuitry, digital circuitry,and/or logic circuitry, the memory and/or memory element storing thecorresponding operational instructions may be embedded within, orexternal to, the circuitry comprising the state machine, analogcircuitry, digital circuitry, and/or logic circuitry. Still further notethat, the memory element stores, and the processing module executes,hard coded and/or operational instructions corresponding to at leastsome of the steps and/or functions illustrated in FIGS. 1-19 B.

Each of the user devices 12-14, the DS processing unit 16, the DSmanaging unit 18, and the storage integrity processing unit 20 may be aportable computing device (e.g., a social networking device, a gamingdevice, a cell phone, a smart phone, a personal digital assistant, adigital music player, a digital video player, a laptop computer, ahandheld computer, a video game controller, and/or any other portabledevice that includes a computing core) and/or a fixed computing device(e.g., a personal computer, a computer server, a cable set-top box, asatellite receiver, a television set, a printer, a fax machine, homeentertainment equipment, a video game console, and/or any type of homeor office computing equipment). Such a portable or fixed computingdevice includes a computing core 26 and one or more interfaces 30, 32,and/or 33. An embodiment of the computing core 26 will be described withreference to FIG. 2.

With respect to the interfaces, each of the interfaces 30, 32, and 33includes software and/or hardware to support one or more communicationlinks via the network 24 and/or directly. For example, interfaces 30support a communication link (wired, wireless, direct, via a LAN, viathe network 24, etc.) between the first type of user device 14 and theDS processing unit 16. As another example, DSN interface 32 supports aplurality of communication links via the network 24 between the DSNmemory 22 and the DS processing unit 16, the first type of user device12, and/or the storage integrity processing unit 20. As yet anotherexample, interface 33 supports a communication link between the DSmanaging unit 18 and any one of the other devices and/or units 12, 14,16, 20, and/or 22 via the network 24.

In general and with respect to data storage, the system 10 supportsthree primary functions: distributed network data storage management,distributed data storage and retrieval, and data storage integrityverification. In accordance with these three primary functions, data canbe distributedly stored in a plurality of physically different locationsand subsequently retrieved in a reliable and secure manner regardless offailures of individual storage devices, failures of network equipment,the duration of storage, the amount of data being stored, attempts athacking the data, etc.

The DS managing unit 18 performs distributed network data storagemanagement functions, which include establishing distributed datastorage parameters, performing network operations, performing networkadministration, and/or performing network maintenance. The DS managingunit 18 establishes the distributed data storage parameters (e.g.,allocation of virtual DSN memory space, distributed storage parameters,security parameters, billing information, user profile information,etc.) for one or more of the user devices 12-14 (e.g., established forindividual devices, established for a user group of devices, establishedfor public access by the user devices, etc.). For example, the DSmanaging unit 18 coordinates the creation of a vault (e.g., a virtualmemory block) within the DSN memory 22 for a user device (for a group ofdevices, or for public access). The DS managing unit 18 also determinesthe distributed data storage parameters for the vault. In particular,the DS managing unit 18 determines a number of slices (e.g., the numberthat a data segment of a data file and/or data block is partitioned intofor distributed storage) and a read threshold value (e.g., the minimumnumber of slices required to reconstruct the data segment).

As another example, the DS managing module 18 creates and stores,locally or within the DSN memory 22, user profile information. The userprofile information includes one or more of authentication information,permissions, and/or the security parameters. The security parameters mayinclude one or more of encryption/decryption scheme, one or moreencryption keys, key generation scheme, and data encoding/decodingscheme.

As yet another example, the DS managing unit 18 creates billinginformation for a particular user, user group, vault access, publicvault access, etc. For instance, the DS managing unit 18 tracks thenumber of times user accesses a private vault and/or public vaults,which can be used to generate a per-access bill. In another instance,the DS managing unit 18 tracks the amount of data stored and/orretrieved by a user device and/or a user group, which can be used togenerate a per-data-amount bill.

The DS managing unit 18 also performs network operations, networkadministration, and/or network maintenance. As at least part ofperforming the network operations and/or administration, the DS managingunit 18 monitors performance of the devices and/or units of the system10 for potential failures, determines the devices and/or unit'sactivation status, determines the devices' and/or units' loading, andany other system level operation that affects the performance level ofthe system 10. For example, the DS managing unit 18 receives andaggregates network management alarms, alerts, errors, statusinformation, performance information, and messages from the devices12-14 and/or the units 16, 20, 22. For example, the DS managing unit 18receives a simple network management protocol (SNMP) message regardingthe status of the DS processing unit 16.

The DS managing unit 18 performs the network maintenance by identifyingequipment within the system 10 that needs replacing, upgrading,repairing, and/or expanding. For example, the DS managing unit 18determines that the DSN memory 22 needs more DS units 36 or that one ormore of the DS units 36 needs updating.

The second primary function (i.e., distributed data storage andretrieval) begins and ends with a user device 12-14. For instance, if asecond type of user device 14 has a data file 38 and/or data block 40 tostore in the DSN memory 22, it send the data file 38 and/or data block40 to the DS processing unit 16 via its interface 30. As will bedescribed in greater detail with reference to FIG. 2, the interface 30functions to mimic a conventional operating system (OS) file systeminterface (e.g., network file system (NFS), flash file system (FFS),disk file system (DFS), file transfer protocol (FTP), web-baseddistributed authoring and versioning (WebDAV), etc.) and/or a blockmemory interface (e.g., small computer system interface (SCSI), internetsmall computer system interface (iSCSI), etc.). In addition, theinterface 30 may attach a user identification code (ID) to the data file38 and/or data block 40.

The DS processing unit 16 receives the data file 38 and/or data block 40via its interface 30 and performs a distributed storage (DS) process 34thereon (e.g., an error coding dispersal storage function). The DSprocessing 34 begins by partitioning the data file 38 and/or data block40 into one or more data segments, which is represented as Y datasegments. For example, the DS processing 34 may partition the data file38 and/or data block 40 into a fixed byte size segment (e.g., 2¹ to2^(n) bytes, where n=>2) or a variable byte size (e.g., change byte sizefrom segment to segment, or from groups of segments to groups ofsegments, etc.).

For each of the Y data segments, the DS processing 34 error encodes(e.g., forward error correction (FEC), information dispersal algorithm,or error correction coding) and slices (or slices then error encodes)the data segment into a plurality of error coded (EC) data slices 42-48,which is represented as X slices per data segment. The number of slices(X) per segment, which corresponds to a number of pillars n, is set inaccordance with the distributed data storage parameters and the errorcoding scheme. For example, if a Reed-Solomon (or other FEC scheme) isused in an n/k system, then a data segment is divided into n slices,where k number of slices is needed to reconstruct the original data(i.e., k is the threshold). As a few specific examples, the n/k factormay be 5/3; 6/4; 8/6; 8/5; 16/10.

For each slice 42-48, the DS processing unit 16 creates a unique slicename and appends it to the corresponding slice 42-48. The slice nameincludes universal DSN memory addressing routing information (e.g.,virtual memory addresses in the DSN memory 22) and user-specificinformation (e.g., user ID, file name, data block identifier, etc.).

The DS processing unit 16 transmits the plurality of EC slices 42-48 toa plurality of DS units 36 of the DSN memory 22 via the DSN interface 32and the network 24. The DSN interface 32 formats each of the slices fortransmission via the network 24. For example, the DSN interface 32 mayutilize an internet protocol (e.g., TCP/IP, etc.) to packetize theslices 42-48 for transmission via the network 24.

The number of DS units 36 receiving the slices 42-48 is dependent on thedistributed data storage parameters established by the DS managing unit18. For example, the DS managing unit 18 may indicate that each slice isto be stored in a different DS unit 36. As another example, the DSmanaging unit 18 may indicate that like slice numbers of different datasegments are to be stored in the same DS unit 36. For example, the firstslice of each of the data segments is to be stored in a first DS unit36, the second slice of each of the data segments is to be stored in asecond DS unit 36, etc. In this manner, the data is encoded anddistributedly stored at physically diverse locations to improved datastorage integrity and security. Further examples of encoding the datasegments will be provided with reference to one or more of FIGS. 2-19 B.

Each DS unit 36 that receives a slice 42-48 for storage translates thevirtual DSN memory address of the slice into a local physical addressfor storage. Accordingly, each DS unit 36 maintains a virtual tophysical memory mapping to assist in the storage and retrieval of data.

The first type of user device 12 performs a similar function to storedata in the DSN memory 22 with the exception that it includes the DSprocessing. As such, the device 12 encodes and slices the data fileand/or data block it has to store. The device then transmits the slices11 to the DSN memory via its DSN interface 32 and the network 24.

For a second type of user device 14 to retrieve a data file or datablock from memory, it issues a read command via its interface 30 to theDS processing unit 16. The DS processing unit 16 performs the DSprocessing 34 to identify the DS units 36 storing the slices of the datafile and/or data block based on the read command. The DS processing unit16 may also communicate with the DS managing unit 18 to verify that theuser device 14 is authorized to access the requested data.

Assuming that the user device is authorized to access the requesteddata, the DS processing unit 16 issues slice read commands to at least athreshold number of the DS units 36 storing the requested data (e.g., toat least 10 DS units for a 16/10 error coding scheme). Each of the DSunits 36 receiving the slice read command, verifies the command,accesses its virtual to physical memory mapping, retrieves the requestedslice, or slices, and transmits it to the DS processing unit 16.

Once the DS processing unit 16 has received a read threshold number ofslices for a data segment, it performs an error decoding function andde-slicing to reconstruct the data segment. When Y number of datasegments has been reconstructed, the DS processing unit 16 provides thedata file 38 and/or data block 40 to the user device 14. Note that thefirst type of user device 12 performs a similar process to retrieve adata file and/or data block.

The storage integrity processing unit 20 performs the third primaryfunction of data storage integrity verification. In general, the storageintegrity processing unit 20 periodically retrieves slices 45, and/orslice names, of a data file or data block of a user device to verifythat one or more slices have not been corrupted or lost (e.g., the DSunit failed). The retrieval process mimics the read process previouslydescribed.

If the storage integrity processing unit 20 determines that one or moreslices is corrupted or lost, it rebuilds the corrupted or lost slice(s)in accordance with the error coding scheme. The storage integrityprocessing unit 20 stores the rebuild slice, or slices, in theappropriate DS unit(s) 36 in a manner that mimics the write processpreviously described.

FIG. 2 is a schematic block diagram of an embodiment of a computing core26 that includes a processing module 50, a memory controller 52, mainmemory 54, a video graphics processing unit 55, an input/output (IO)controller 56, a peripheral component interconnect (PCI) interface 58,at least one IO device interface module 62, a read only memory (ROM)basic input output system (BIOS) 64, and one or more memory interfacemodules. The memory interface module(s) includes one or more of auniversal serial bus (USB) interface module 66, a host bus adapter (HBA)interface module 68, a network interface module 70, a flash interfacemodule 72, a hard drive interface module 74, and a DSN interface module76. Note the DSN interface module 76 and/or the network interface module70 may function as the interface 30 of the user device 14 of FIG. 1.Further note that the IO device interface module 62 and/or the memoryinterface modules may be collectively or individually referred to as IOports.

The processing module 50 may be a single processing device or aplurality of processing devices. Such a processing device may be amicroprocessor, micro-controller, digital signal processor,microcomputer, central processing unit, field programmable gate array,programmable logic device, state machine, logic circuitry, analogcircuitry, digital circuitry, and/or any device that manipulates signals(analog and/or digital) based on hard coding of the circuitry and/oroperational instructions. The processing module 50 may have anassociated memory and/or memory element, which may be a single memorydevice, a plurality of memory devices, and/or embedded circuitry of theprocessing module 50. Such a memory device may be a read-only memory,random access memory, volatile memory, non-volatile memory, staticmemory, dynamic memory, flash memory, cache memory, and/or any devicethat stores digital information. Note that if the processing module 50includes more than one processing device, the processing devices may becentrally located (e.g., directly coupled together via a wired and/orwireless bus structure) or may be distributedly located (e.g., cloudcomputing via indirect coupling via a local area network and/or a widearea network). Further note that when the processing module 50implements one or more of its functions via a state machine, analogcircuitry, digital circuitry, and/or logic circuitry, the memory and/ormemory element storing the corresponding operational instructions may beembedded within, or external to, the circuitry comprising the statemachine, analog circuitry, digital circuitry, and/or logic circuitry.Still further note that, the memory element stores, and the processingmodule 50 executes, hard coded and/or operational instructionscorresponding to at least some of the steps and/or functions illustratedin FIGS. 1-19 B.

FIG. 3 is a schematic block diagram of an embodiment of a dispersedstorage (DS) processing module 34 of user device 12 and/or of the DSprocessing unit 16. The DS processing module 34 includes a gatewaymodule 78, an access module 80, a grid module 82, and a storage module84. The DS processing module 34 may also include an interface 30 and theDSnet interface 32 or the interfaces 68 and/or 70 may be part of user 12or of the DS processing unit 14. The DS processing module 34 may furtherinclude a bypass/feedback path between the storage module 84 to thegateway module 78. Note that the modules 78-84 of the DS processingmodule 34 may be in a single unit or distributed across multiple units.

In an example of storing data, the gateway module 78 receives anincoming data object that includes a user ID field 86, an object namefield 88, and the data field 40 and may also receive correspondinginformation that includes a process identifier (e.g., an internalprocess/application ID), metadata, a file system directory, a blocknumber, a transaction message, a user device identity (ID), a dataobject identifier, a source name, and/or user information. The gatewaymodule 78 authenticates the user associated with the data object byverifying the user ID 86 with the managing unit 18 and/or anotherauthenticating unit.

When the user is authenticated, the gateway module 78 obtains userinformation from the management unit 18, the user device, and/or theother authenticating unit. The user information includes a vaultidentifier, operational parameters, and user attributes (e.g., userdata, billing information, etc.). A vault identifier identifies a vault,which is a virtual memory space that maps to a set of DS storage units36. For example, vault 1 (i.e., user 1's DSN memory space) includeseight DS storage units (X=8 wide) and vault 2 (i.e., user 2's DSN memoryspace) includes sixteen DS storage units (X=16 wide). The operationalparameters may include an error coding algorithm, the width n (number ofpillars X or slices per segment for this vault), a read threshold T, awrite threshold, an encryption algorithm, a slicing parameter, acompression algorithm, an integrity check method, caching settings,parallelism settings, and/or other parameters that may be used to accessthe DSN memory layer.

The gateway module 78 uses the user information to assign a source name35 to the data. For instance, the gateway module 60 determines thesource name 35 of the data object 40 based on the vault identifier andthe data object. For example, the source name may contain a fileidentifier (ID), a vault generation number, a reserved field, and avault identifier (ID). As another example, the gateway module 78 maygenerate the file ID based on a hash function of the data object 40.Note that the gateway module 78 may also perform message conversion,protocol conversion, electrical conversion, optical conversion, accesscontrol, user identification, user information retrieval, trafficmonitoring, statistics generation, configuration, management, and/orsource name determination.

The access module 80 receives the data object 40 and creates a series ofdata segments 1 through Y 90-92 in accordance with a data storageprotocol (e.g., file storage system, a block storage system, and/or anaggregated block storage system). The number of segments Y may be chosenor randomly assigned based on a selected segment size and the size ofthe data object. For example, if the number of segments is chosen to bea fixed number, then the size of the segments varies as a function ofthe size of the data object. For instance, if the data object is animage file of 4,194,304 eight bit bytes (e.g., 33,554,432 bits) and thenumber of segments Y=131,072, then each segment is 256 bits or 32 bytes.As another example, if segment sized is fixed, then the number ofsegments Y varies based on the size of data object. For instance, if thedata object is an image file of 4,194,304 bytes and the fixed size ofeach segment is 4,096 bytes, the then number of segments Y=1,024. Notethat each segment is associated with the same source name.

The grid module 82 receives the data segments and may manipulate (e.g.,compression, encryption, cyclic redundancy check (CRC), etc.) each ofthe data segments before performing an error coding function of theerror coding dispersal storage function to produce a pre-manipulateddata segment. After manipulating a data segment, if applicable, the gridmodule 82 error encodes (e.g., Reed-Solomon, Convolution encoding,Trellis encoding, etc.) the data segment or manipulated data segmentinto X error coded data slices 42-44.

The value X, or the number of pillars (e.g., X=16), is chosen as aparameter of the error coding dispersal storage function. Otherparameters of the error coding dispersal function include a readthreshold T, a write threshold W, etc. The read threshold (e.g., T=10,when X=16) corresponds to the minimum number of error-free error codeddata slices required to reconstruct the data segment. In other words,the DS processing module 34 can compensate for X−T (e.g., 16−10=6)missing error coded data slices per data segment. The write threshold Wcorresponds to a minimum number of DS storage units that acknowledgeproper storage of their respective data slices before the DS processingmodule indicates proper storage of the encoded data segment. Note thatthe write threshold is greater than or equal to the read threshold for agiven number of pillars (X).

For each data slice of a data segment, the grid module 82 generates aunique slice name 37 and attaches it thereto. The slice name 37 includesa universal routing information field and a vault specific field and maybe 48 bytes (e.g., 24 bytes for each of the universal routinginformation field and the vault specific field). As illustrated, theuniversal routing information field includes a slice index, a vault ID,a vault generation, and a reserved field. The slice index is based onthe pillar number and the vault ID and, as such, is unique for eachpillar (e.g., slices of the same pillar for the same vault for anysegment will share the same slice index). The vault specific fieldincludes a data name, which includes a file ID and a segment number(e.g., a sequential numbering of data segments 1-Y of a simple dataobject or a data block number).

Prior to outputting the error coded data slices of a data segment, thegrid module may perform post-slice manipulation on the slices. Ifenabled, the manipulation includes slice level compression, encryption,CRC, addressing, tagging, and/or other manipulation to improve theeffectiveness of the computing system.

When the error coded data slices of a data segment are ready to beoutputted, the grid module 82 determines which of the DS storage units36 will store the EC data slices based on a dispersed storage memorymapping associated with the user's vault and/or DS storage unitattributes. The DS storage unit attributes may include availability,self-selection, performance history, link speed, link latency,ownership, available DSN memory, domain, cost, a prioritization scheme,a centralized selection message from another source, a lookup table,data ownership, and/or any other factor to optimize the operation of thecomputing system. Note that the number of DS storage units 36 is equalto or greater than the number of pillars (e.g., X) so that no more thanone error coded data slice of the same data segment is stored on thesame DS storage unit 36. Further note that EC data slices of the samepillar number but of different segments (e.g., EC data slice 1 of datasegment 1 and EC data slice 1 of data segment 2) may be stored on thesame or different DS storage units 36.

The storage module 84 performs an integrity check on the outboundencoded data slices and, when successful, identifies a plurality of DSstorage units based on information provided by the grid module 82. Thestorage module 84 then outputs the encoded data slices 1 through X ofeach segment 1 through Y to the DS storage units 36. Each of the DSstorage units 36 stores its EC data slice(s) and maintains a localvirtual DSN address to physical location table to convert the virtualDSN address of the EC data slice(s) into physical storage addresses.

In an example of a read operation, the user device 12 and/or 14 sends aread request to the DS processing unit 14, which authenticates therequest. When the request is authentic, the DS processing unit 14 sendsa read message to each of the DS storage units 36 storing slices of thedata object being read. The slices are received via the DSnet interface32 and processed by the storage module 84, which performs a parity checkand provides the slices to the grid module 82 when the parity check wassuccessful. The grid module 82 decodes the slices in accordance with theerror coding dispersal storage function to reconstruct the data segment.The access module 80 reconstructs the data object from the data segmentsand the gateway module 78 formats the data object for transmission tothe user device.

FIG. 4 is a schematic block diagram of an embodiment of a grid module 82that includes a control unit 73, a pre-slice manipulator 75, an encoder77, a slicer 79, a post-slice manipulator 81, a pre-slice de-manipulator83, a decoder 85, a de-slicer 87, and/or a post-slice de-manipulator 89.Note that the control unit 73 may be partially or completely external tothe grid module 82. For example, the control unit 73 may be part of thecomputing core at a remote location, part of a user device, part of theDS managing unit 18, or distributed amongst one or more DS storageunits.

In an example of write operation, the pre-slice manipulator 75 receivesa data segment 90-92 and a write instruction from an authorized userdevice. The pre-slice manipulator 75 determines if pre-manipulation ofthe data segment 90-92 is required and, if so, what type. The pre-slicemanipulator 75 may make the determination independently or based oninstructions from the control unit 73, where the determination is basedon a computing system-wide predetermination, a table lookup, vaultparameters associated with the user identification, the type of data,security requirements, available DSN memory, performance requirements,and/or other metadata.

Once a positive determination is made, the pre-slice manipulator 75manipulates the data segment 90-92 in accordance with the type ofmanipulation. For example, the type of manipulation may be compression(e.g., Lempel-Ziv-Welch, Huffman, Golomb, fractal, wavelet, etc.),signatures (e.g., Digital Signature Algorithm (DSA), Elliptic Curve DSA,Secure Hash Algorithm, etc.), watermarking, tagging, encryption (e.g.,Data Encryption Standard, Advanced Encryption Standard, etc.), addingmetadata (e.g., time/date stamping, user information, file type, etc.),cyclic redundancy check (e.g., CRC32), and/or other data manipulationsto produce the pre-manipulated data segment.

The encoder 77 encodes the pre-manipulated data segment 92 using aforward error correction (FEC) encoder (and/or other type of erasurecoding and/or error coding) to produce an encoded data segment 94. Theencoder 77 determines which forward error correction algorithm to usebased on a predetermination associated with the user's vault, a timebased algorithm, user direction, DS managing unit direction, controlunit direction, as a function of the data type, as a function of thedata segment 92 metadata, and/or any other factor to determine algorithmtype. The forward error correction algorithm may be Golay,Multidimensional parity, Reed-Solomon, Hamming, Bose Ray ChauduriHocquenghem (BCH), Cauchy-Reed-Solomon, or any other FEC encoder. Notethat the encoder 77 may use a different encoding algorithm for each datasegment 92, the same encoding algorithm for the data segments 92 of adata object, or a combination thereof.

The encoded data segment 94 is of greater size than the data segment 92by the overhead rate of the encoding algorithm by a factor of X/T, whereX is the width or number of slices, and T is the read threshold. In thisregard, the corresponding decoding process can accommodate at most X−Tmissing EC data slices and still recreate the data segment 92. Forexample, if X=16 and T=10, then the data segment 92 will be recoverableas long as 10 or more EC data slices per segment are not corrupted.

The slicer 79 transforms the encoded data segment 94 into EC data slicesin accordance with the slicing parameter from the vault for this userand/or data segment 92. For example, if the slicing parameter is X=16,then the slicer 79 slices each encoded data segment 94 into 16 encodedslices.

The post-slice manipulator 81 performs, if enabled, post-manipulation onthe encoded slices to produce the EC data slices. If enabled, thepost-slice manipulator 81 determines the type of post-manipulation,which may be based on a computing system-wide predetermination,parameters in the vault for this user, a table lookup, the useridentification, the type of data, security requirements, available DSNmemory, performance requirements, control unit directed, and/or othermetadata. Note that the type of post-slice manipulation may includeslice level compression, signatures, encryption, CRC, addressing,watermarking, tagging, adding metadata, and/or other manipulation toimprove the effectiveness of the computing system.

In an example of a read operation, the post-slice de-manipulator 89receives at least a read threshold number of EC data slices and performsthe inverse function of the post-slice manipulator 81 to produce aplurality of encoded slices. The de-slicer 87 de-slices the encodedslices to produce an encoded data segment 94. The decoder 85 performsthe inverse function of the encoder 77 to recapture the data segment90-92. The pre-slice de-manipulator 83 performs the inverse function ofthe pre-slice manipulator 75 to recapture the data segment 90-92.

FIG. 5 is a diagram of an example of slicing an encoded data segment 94by the slicer 79. In this example, the encoded data segment 94 includesthirty-two bits, but may include more or less bits. The slicer 79disperses the bits of the encoded data segment 94 across the EC dataslices in a pattern as shown. As such, each EC data slice does notinclude consecutive bits of the data segment 94 reducing the impact ofconsecutive bit failures on data recovery. For example, if EC data slice2 (which includes bits 1, 5, 9, 13, 17, 25, and 29) is unavailable(e.g., lost, inaccessible, or corrupted), the data segment can bereconstructed from the other EC data slices (e.g., 1, 3 and 4 for a readthreshold of 3 and a width of 4).

FIG. 6 is a schematic block diagram of another embodiment of a computingsystem where one or more user devices may store and retrieve data from aplurality of dispersed storage networks (DSNs). Such a system includesone or more user devices 12, one or more user devices 14, a dispersedstorage (DS) processing unit 102, a management authority 104, a namingauthority 106, a billing authority 108, a security authority 110, apublishing authority 112, a network 24, and a plurality of DSN systems1-D. Each of the DSN systems 1-D includes a plurality of DS units 36, aDS processing unit 16, a DS managing unit 18, and a storage integrityprocessing unit 20. The DS processing unit facilitates access to theplurality of DSNs 1-D for one or more user devices 14.

Each of the management authority 104, the naming authority 106, thebilling authority 108, the security authority 110, and the publishingauthority 112 may be a portable computing device (e.g., a socialnetworking device, a gaming device, a cell phone, a smart phone, apersonal digital assistant, a digital music player, a digital videoplayer, a laptop computer, a handheld computer, a video game controller,and/or any other portable device that includes a computing core) and/ora fixed computing device (e.g., a personal computer, a computer server,a cable set-top box, a satellite receiver, a television set, a printer,a fax machine, home entertainment equipment, a video game console,and/or any type of home or office computing equipment). Such a portableor fixed computing device includes a computing core 26 and one or moreinterfaces 30, 32, and 33.

A user device 12 of the one or more user devices 12 affiliates with aDSN system of the plurality of DSNs 1-D. For example, user device 12affiliates with a home or local DSN system 2. As such, user device 12normally stores and retrieve encoded data slices to/from a plurality ofDS units 36 of DSN system 2 via the network 24. As another example, userdevice 14 stores and retrieves a data object to/from DS processing unit16 of DSN system 1 via the network 24. As another example, user device14 stores and retrieves the data object to/from the DS processing unit102. Such a DS processing unit 102 may not be directly associated with aplurality of DS units 36. As such, DS processing unit 102 may beconsidered as a still further DSN system without specifically assignedDS units 36. As an implementation example, DS processing unit 102 isassociated with an internet service provider (ISP) portal such that userdevice 14 gains access to the internet through a portal associated withthe DS processing unit 102. The method of operation of the DS processingunit 102 is discussed in greater detail with reference to FIGS. 15 A-15B.

In another example, the user devices 12-14 affiliate with one or moreother DSN system(s) in addition to a local/home DSN system to facilitateaccess to DS units 36 of two or more DSN systems. For example, userdevice 12 affiliates with DSN system 1 and DSN system 2 such that theuser device 12 may store and retrieve data slices to the DS units 36 ofDSN system 1 and/or DSN system 2. For instance, user device 12 storesdata slices of each pillar of a data segment in one or both of DSNsystem 1 and DSN system 2. As another instance, user device 12 storesdata slices of 5 pillars in DSN system 1 and nothing in DSN system 2when a pillar width is 5. As yet another instance, user device 12 storesdata slices of 5 pillars in DSN system 1 and stores replicated dataslices of all 5 pillars in DSN system 2 when the pillar width is 5. As astill further instance, user device 12 stores data slices of a first 3of 5 pillars in DSN system 1 and stores data slices of a next 2 of 5pillars in DSN system 2 when the pillar width is 5. The method ofoperation of a DS processing 34 of user device 12 and/or of DSprocessing 102 to store and/or retrieve data slices to a plurality ofDSN systems is discussed in greater detail with reference to FIGS. 7-19B.

Such a management authority 104 functions includes one or more ofexchange of management information between two or more DS managing units18, aggregation of management information, reporting of managementinformation, provisioning of global vaults, provisioning of globalidentities, allocation of storage resources, and establishment of globaloperational parameters utilized by two or more of the DSN systems.

Such a naming authority 106 functions includes one or more of allocationof global virtual DSN address ranges, allocation of regional virtual DSNaddress ranges, exchange of naming information between two or more DSmanaging units 18, aggregation of naming information, reporting ofnaming information, and establishment of global naming parametersutilized by two or more of the DSN systems. For example, the namingauthority 106 allocates a portion of a DSN virtual address range to becommon as a global virtual DSN address range across each of the DSNsystems 1-D. As another example, the naming authority 106 allocates asecond portion of the DSN virtual address range to be common as aregional virtual DSN address range across a first portion and a secondportion of the DSN systems 1-D. As such, a regional virtual DSN addressrange may be shared amongst two or more DSN systems. The method ofoperation of the naming authority 106 is discussed in greater detailwith reference to FIGS. 16 A-16 B.

Such a billing authority 108 functions includes one or more ofallocation of resources, exchanging of billing information between twoor more DS managing units 18, determination of usage information,aggregation of billing information, balancing billing credits anddebits, establishment of billing rates, utilization of billing rates,reporting of billing information, and establishment of global billingparameters utilized by two or more of the DSN systems. For example, thebilling authority 108 determines billing information for user device 14based on received DSN system 1 usage information for user device 14 andreceived DSN system 3 usage information for user device 14. The methodof operation of the billing authority 108 is discussed in greater detailwith reference to FIGS. 14 A-14 B.

Such a security authority 110 functions includes one or more of thecreation of a root certificate, the processing of a digital signingrequest from an element of a DSN system, processing of a digital signingrequest from a user device 12-14, certificate validation, and rootcertificate distribution. For example, the security authority 110processes a digital signing request from a DS managing unit 18 of DSNsystem 6. Next, the security authority 110 sends a root certificate toDS managing unit 18 when the security authority 110 determines that thedigital signing request is valid. The method of operation of thesecurity authority 110 is discussed in greater detail with reference toFIGS. 17 A-19 B.

Such a publishing authority 112 functions includes one or more ofdetermination of storage locations of data slices for a data object,determination of replication of pillars across two or more of the DSNsystems, a determination of estimated optimized DS unit 36 accessperformance, publication of storage location information, publication ofperformance information, and allocation of estimated performanceinformation. For example, the publishing authority 112 determines thatdata slices of each pillar of a stored data object are stored in a setof DS units 36 of DSN system 2 in are replicated in a set of DS units 36of DSN system 7. Next, the publishing authority 112 determines which ofthe set of DS units 36 of DSN system 2 and the set of DS units 36 of DSNsystem 7 have a best-estimated access performance with reference to DSprocessing unit 102. Next, publishing authority 112 publishes estimatedaccess performance information with reference to DS processing unit 102such that DS processing unit 102 may utilize the estimated accessperformance information in determining which DSN system to subsequentlyaccess (e.g., retrieve, store, delete, list) which pillars. The methodof operation of the publishing authority 112 is discussed in greaterdetail with reference to FIGS. 11 A-11 B.

FIG. 7 is a flowchart illustrating an example of storing data. Themethod begins with step 114 word processing module receives a store datarequest message from any one of a user device, a dispersed storage (DS)processing unit, a storage integrity processing unit, a DS managingunit, and a DS unit. Such a store data request message may include oneor more of a user identifier (ID), a request code, a data ID, a dataobject, a data segment, a data block, a data type indicator, a datahash, a vault ID, a data size indicator, a priority indicator, asecurity indicator, storage requirements, and a performance indicator.

The method continues at step 116 where the processing module determinesmetadata. Such metadata may describe the data (e.g., the indicators anddescriptors of the data object) and/or requirements for storage access(e.g., priority, performance, availability, reliability, geographicrequirements). Such a determination may be based on one or more of avault lookup, an affiliation indicator, a command, a message, apredetermination, a data object analysis, the data object name, the dataobject size, a data type, the data object, input metadata, the priorityindicator, the security indicator, the performance indicator, and thestorage requirements.

The method continues at step 118 where the processing module determinesa replication factor. Such a replication factor indicates how manycopies of the data shall be stored (e.g., as multiple sets of encodeslices). Such a determination may be based on one or more of the data,requirements, the metadata, a message, a lookup, information received inthe store data object message, and replication guidelines. For example,the processing module determines the replication factor to be 2 when therequirements indicate that a higher level of reliability is required. Asanother example, the processing module determines the replication factorto be 5 when the requirements indicate that broad geographicdistribution is required to enable favorable copy retrieval performance(e.g., a desirable access latency).

The method continues at step 120 where the processing module identifiesa plurality of dispersed storage networks (DSNs) for storing copies ofdispersed storage encoded data based on global data retrieval accessesof the copies of the dispersed storage encoded data. Such adetermination may be based on one or more of the replication factor,available DSN systems, DSN system attributes, the data, therequirements, the metadata, a message, and a lookup. For example, theprocessing module determines to store data slices and replicated dataslices in DSN systems 1 and 6 when the DSN system attributes match thestorage requirements (e.g., closer geographic proximity of the DSNsystems to the user device). The processing module may determine theglobal data retrieval accesses based on one or more of quantity ofretrieval accesses, a data type of the data, a data size indicator ofthe data, a user device geographic affiliation, a dispersed storageprocessing unit geographic affiliation, a geographic requirement, a DSNgeographic affiliation, a retrieval latency requirement, a DSNperformance level, an availability requirement, a reliabilityrequirement, a predetermination, and a user identifier (ID).

The method continues at step 122 where the processing module determinesDS unit storage sets for each of the DSN systems. Such a determinationmay be based on one or more of the identified DSNs, the replicationfactor, available DS unit storage sets, DS unit storage set attributes,the data object, the requirements, the metadata, a message, and alookup. For example, the processing module determines the DS unitstorage sets that are closest to an associated DS processing modulebased on the DS unit storage set attributes.

The method continues at step 124 where the processing module determinesa set of error coding dispersal storage parameters for at least one ofthe plurality of DSNs based on local data retrieval accesses allocatedto the at least one of the plurality of DSNs. The processing moduledetermines the local data retrieval accesses for each of the pluralityof DSNs based on an allocation portion of the global data retrievalaccesses the processing module determines the allocation portion basedon one or more of the global data retrieval accesses, informationreceived in the store data request message, the data, the replicationfactor, the metadata, the DSN systems, the DS unit storage sets, a vaultlookup, a command, a message, and a predetermination.

At step 124 processing module determines a second set of error codingdispersal storage parameters for at least a second one of the pluralityof DSNs based on second local data retrieval accesses allocated to theat least the second one of the plurality of DSNs. For example, theprocessing module determines a common decode threshold for each of theset and second set of error coding dispersal storage parameters toenable utilization of replicated slices between DSNs. Next, theprocessing module determines a first plurality of parameter subsets forthe set of error coding dispersal storage parameters, which includes afirst pillar width, a first write threshold, and a first read thresholdand the processing module determines a second plurality of parametersubsets for the second set of error coding dispersal storage parameters,which includes a second pillar width, a second write threshold, and asecond read threshold.

The method continues at step 126 where the processing module facilitatesstorage of the error coding dispersal storage parameters and/orfacilitates storage of a plurality of DSN identifiers (IDs), whereineach DSN ID of the plurality of DSN IDs corresponds to a DSN of theplurality of DSNs (e.g., to facilitate subsequent access to the copies).The method continues at step 128 where the processing module encodesdata in accordance with the set of error coding dispersal storageparameters to produce a copy of the copies of the dispersed storageencoded data. The method continues at step 130 where the processingmodule outputs the copy of the copies of the dispersed storage encodeddata to the at least one of the plurality of DSNs.

FIG. 8 A is another flowchart illustrating another example of storingdata, which includes similar steps to FIG. 7. The method begins withsteps 114, 116, 118, and 120 of FIG. 7 where a processing modulereceives a store data request message, determines metadata, determinesthe replication factor, and identifies a plurality of dispersed storagenetworks (DSNs). The method continues at step 140 where the processingmodule determines a local DS unit storage set for a local DSN of theDSNs. Such a determination may be based on one or more of the local DSN,the replication factor, available DS unit storage sets, DS unit storageset attributes, data, requirements, the metadata, a message, and alookup. For example, the processing module determines the local DS unitstorage set that is closest to an associated user device based on localDS unit storage set geographic attributes.

The method continues at step 142 where the processing module determinesthat a set of the plurality of DSNs have substantially similar localdata retrieval accesses. Next, the processing module determines a set oferror coding dispersal storage parameters for a set of the plurality ofDSNs. The method continues at step 126 of FIG. 7 where the processingmodule saves the set of error coding dispersal storage parameters.

The method continues at step 146 where the processing module encodes, byone of the set of DSNs, data in accordance with the set of error codingdispersal storage parameters to produce a plurality of sets of encodeddata slices. The method continues at step 148 where the processingmodule stores, by the one of the set of DSNs, the plurality of sets ofencoded data slices within the one of the set of DSNs. For example, theprocessing module sends the plurality of sets of encoded data slices tothe local DS unit storage set for storage therein.

The method continues at step 150 where the processing module outputs, bythe one of the set of DSNs, the plurality of sets of encoded data slicesto other DSNs of the set of the plurality of DSNs for storage therein(e.g., when storing replicated slices). For example, the processingmodule sends all pillars of the plurality of sets of encoded data slicesto the other DSNs for storage therein. As another example, theprocessing module sends an encoded data slice of a first pillar to a DSunit of the local DSN system and sends the encoded data slice to asecond DSN system for storage in a DS unit of the second DSN system. Asyet another example, the processing module sends a decode thresholdnumber of encoded data slices to DS units of the local DSN system andsends other encoded data slices to a second DSN system for storage in DSunits of the second DSN system. As stills another example, theprocessing module sends the encoded data slices such that all pillarsare stored in a similar geographic region but in two or more DSNsystems. For instance, the first half of the pillars may be stored in DSunits of the desired geographic region in the first DSN system and thesecond half of the pillars may be stored in DS units of the desiredgeographic region in the second DSN system.

FIG. 8 B is another flowchart illustrating an example of authorizingencoded data slice storage. The method begins with step 152 where aprocessing module receives, by a second one of at least one of aplurality of dispersed storage networks (DSNs), a copy of copies ofdispersed storage encoded data from a first one of the at least one ofthe plurality of DSNs. Such a copy may include one or more of arequester identifier (ID), one or more sets of encoded data slices, anderror coding dispersal storage parameters.

The method continues at step 154 where the processing module determineswhether a requester is authorized to access the second one of the atleast one of the plurality of DSNs. Such a determination may be based onone or more of the requester ID, a vault ID, a user ID, a data objectname, a slice name, a source name, a root certificate, a DSN digitalcertificate, a user device certificate, a dispersed storage (DS)processing module of the first DSN system certificate, a securityauthority query, a DS managing unit query, an authorization recordlookup, a command, and a message. For example, the processing moduledetermines that the requester is authorized to the second one of the atleast one of the plurality of DSNs when each certificate is valid andthe requester ID is authorized to access the second one of the at leastone of the plurality of DSNs as indicated by a authorization recordlookup.

The method branches to step 158 when the processing module determinesthat the requester is authorized to access the second one of the atleast one of the plurality of DSNs. The method ends with step 156 whenthe processing module determines that the requester is not authorized toaccess the second one of the at least one of the plurality of DSNs. Atstep 156, the processing module sends an un-authorized message to one ormore of the requester, a DS processing module, a DS managing unit, afirst DSN system, a management authority, and a security authority.

The method continues at step 158 where the processing module determines,by the second one of the at least one of the plurality of DSNs, a set oflocal DS units. Such a determination may be based on one or more ofreceived error coding dispersal storage parameters, identified DSNsystems, a replication factor, available DS unit storage sets (e.g. ofthe second one of the at least one of the plurality of DSNs), DS unitstorage set attributes, encoded data slices, storage requirements,metadata, a message, and a lookup. For example, the processing moduledetermines the local DS unit storage set that is closest to a DSprocessing module based on the local DS unit storage set attributes. Themethod continues at step 160 where the processing module stores aplurality of sets of encoded data slices of the copy of the copies ofthe dispersed storage encoded data within the set of local DS units.

In addition, the processing module may identify, by the second one ofthe at least one of the plurality of DSNs, a third one of the at leastone of the plurality of DSNs and output, by the second one of the atleast one of the plurality of DSNs, the copy of the copies of thedispersed storage encoded data to the third one of the at least one ofthe plurality of DSNs.

FIG. 9 is a flowchart illustrating an example of retrieving data, whichinclude similar steps to FIG. 7. The method begins at step 162 where aprocessing module receives a retrieve data request message from arequester (e.g., from a user device). Such a retrieve data requestmessage may include one or more of a user ID, a request, a data objectname, a date to identifier (ID), a data type indicator, a data objecthash, a vault ID, a data size indicator, a priority indicator, asecurity indicator, storage requirements, and a performance indicator.The method continues with steps 116-124 of FIG. 7 where the processingmodule determines metadata, determines a plurality of dispersed storagenetworks (DSNs), determines dispersed storage (DS) storage sets, anddetermines error coding dispersal storage parameters.

The method continues at step 172 where the processing module selects DSunits from the DS unit storage sets. Such a selection may be based onone or more of the metadata, the error coding dispersal storageparameters, retrieval requirements, the DSN systems, a DSN lookup tableaccess, the DS unit storage sets, DS unit attributes, DS unit status,estimated DS unit performance, estimated DS units reliability, estimatedDS unit availability, and DS unit cost. Encoded data slice may beretrieved from two or more DS units where the two or more DS storageunits are part of two or more DSN systems. As such, a data slice and acopy of the data slice may have been replicated in two or more DS units.For example, the processing module selects DS units corresponding toless than a decode threshold number of pillars from a first DSN systemwhere the DS units have favorable estimated performance and theprocessing module selects DS units from a second DSN systemcorresponding to pillars to complete a decode threshold number ofpillars in total from the two DSN systems such that DS units of thesecond DSN system have favorable estimated performance.

The method continues at step 174 where the processing module retrievesat least a decode threshold number of encoded data slices from theselected DS units by sending the DS units one or more retrieve encodeddata slice request messages. Next, the processing module receives atleast a decode threshold number of encoded data slices from at leastsome of the selected DS units. The method continues at step 176 wherethe processing module dispersed storage error decodes the at least thedecode threshold number of encoded data slices to reproduce data inaccordance with the error coding dispersal storage parameters. Themethod continues at step 178 where the processing module sends thereproduced data to the requester.

FIG. 10 is a flowchart illustrating an example of rebuilding data thatincludes similar steps to FIG. 7. The method begins with step 180 wherea processing module determines a slice name of an encoded slice to berebuilt within a first dispersed storage network (DSN). Such determiningincludes at least one of determining a slice name of a missing encodedslice as the slice name of the encoded slice to be rebuilt, determininga slice name of an encoded slice associated with an unfavorableintegrity indication to produce the slice name of the encoded slice tobe rebuilt, determining a slice name of an encoded slice associated withan unfavorable comparison of retrieved replicated encoded slices fromtwo or more DSNs to produce the slice name of the encoded slice to berebuilt, and receiving the slice name of the encoded slice to berebuilt. The method continues with steps 120-124 of FIG. 7 where theprocessing module determines DSN systems, determines dispersed storage(DS) unit storage sets, and determines error coding dispersal storageparameters.

The method continues at step 188 where the processing module determineswhether a corresponding copy of the encoded slice is stored in a secondDSN. Such determining begins with determining whether the first andsecond DSNs are each storing an encoded copy of a data file (e.g., basedon the determination of the DSN systems, and a slice name to DSN tablelookup). Next, the processing module determines whether the first andsecond DSNs utilizes a similar set of error coding dispersal storageparameters to produce the encoded copy of the data file that includes aplurality of sets of encoded slices, when the first and second DSNs areeach storing the encoded copy of the data file. The processing moduledetermines that the corresponding copy of the encoded slice is stored inthe second DSN when the first and second DSNs are using the similar setof error coding dispersal storage parameters. The method continues tostep 190 when the processing module determines that the correspondingcopy of encoded slice is stored in the second DSN.

Next, the processing module determines whether the first and second DSNsutilizes a similar decoding threshold when the first and second DSNs arenot using the similar set of error coding dispersal storage parameters.The processing module determines whether the encoded slice is an encodeddata slice or an encoded parity slice when the first and second DSNsutilize the similar decoding threshold. The processing module determinesthat the corresponding copy of the encoded slice is not stored in thesecond DSN when the encoded slice is the encoded parity slice (e.g.,different pillar widths lead to different party slices). The methodbranches to step 195 when the processing module determines that thecorresponding copy of encoded slice is not stored in the second DSN. Theprocessing module determines that the corresponding copy of the encodedslice is stored in the second DSN when the encoded slice is the encodeddata slice (e.g., same size unity matrix is included in encodingmatrices utilized to encode data into the same encoded data slicespillar by pillar for the decode threshold number of encoded dataslices). The method continues to step 190 when the processing moduledetermines that the corresponding copy of encoded slice is stored in thesecond DSN.

The method continues at step 190 where the processing module selects acorresponding DS unit from a DS unit storage set associated with thesecond DSN of the DS unit storage sets. Such a selection may be based onone or more of the slice name, a pillar identifier (ID) associated withthe slice name, a DS unit to pillar ID association, a slice name to DSunit table lookup, metadata, the error coding dispersal storageparameters, rebuild requirements, the DSN systems, the DS unit storagesets, DS unit attributes, DS unit status, estimated DS unit performance,estimated DS units reliability, estimated DS unit availability, and DSunit cost.

The method continues at step 192 where the processing module retrievesthe corresponding copy of the encoded slice from the second DSN when thecorresponding copy of the encoded slice is stored in the second DSN. Forexample, the processing module sends an encoded slice read requestmessage to the DS unit of the second DSN, wherein the message includesthe slice name. Next, the processing module receives the encoded slice.The method continues at step 194 where the processing module stores thecorresponding copy of the encoded slice as a rebuilt encoded slicewithin the first DSN. For example, the processing module sends a writerequest message to a corresponding DS unit of the first DSN, wherein themessage includes the encoded slice and the slice name.

The method continues at step 195 where the processing module requests aset of encoded slices from at least one of the first and second DSNs,wherein the set of encoded slices includes the encoded slice when thecorresponding copy of encoded slice is not stored in the second DSN.Such requesting may include one or more of determining whether torequest the set of slices from the first DSN, the second DSN, or acombination of the first and second DSNs based on network status andsending a set of encoded slice read request messages, wherein therequest messages include a corresponding set of slice names. Such a setof slice names includes slice names associated with a decode thresholdnumber of encoded slices subsequently utilized to rebuild the encodedslice and may not include the slice name. Such a network status mayinclude one or more of a network utilization level, a network bandwidthavailability indicator, a DSN status indicator, a DSN performance levelindicator, and a DSN capacity indicator.

The method continues at step 196 where the processing module receives adecode threshold number of encoded slices of a set of encoded slices toproduce received encoded slices. The method continues at step 197 wherethe processing module rebuilds the encoded slice from the receivedencoded slices to produce a rebuilt encoded slice. Such rebuilding maybe accomplished by a processing module of the first DSN or the secondDSN. The method continues at step 198 where the processing module storesthe rebuilt encoded slice in the first DSN.

As an example of steps 195-198, the first DSN requests the set ofencoded slices from the at least one of the first and second DSNs andthe first DSN receives the received encoded slices from the at least oneof the first and second DSNs. Next, the first DSN rebuilds the encodedslice from the received encoded slices to produce a rebuilt encodedslice and the first DSN stores the rebuilt encoded slice in the firstDSN.

As another example of steps 195-198, the second DSN requests the set ofencoded slices from the at least one of the first and second DSNs andthe second DSN receives the received encoded slices from the at leastone of the first and second DSNs. Next, the second DSN rebuilds theencoded slice from the received encoded slices to produce a rebuiltencoded slice and the second DSN sends the rebuilt encoded slice to thefirst DSN. Next, the first DSN stores the rebuilt encoded slice in thefirst DSN.

FIG. 11 A is a flowchart illustrating an example of publishing storageinformation, which includes similar steps to FIG. 7. The method beginswith steps 120-122 of FIG. 7 where a processing module (e.g., of apublishing authority) determines a plurality of dispersed storagenetworks (DSNs) of a computing system network and determines a pluralityof dispersed storage (DS) unit storage sets within each of the DSNs. Themethod continues at step 208 where the processing module identifies setsof DS units for each of the plurality of dispersed storage networks(DSNs) in the computing system network, wherein a set of the sets of DSunit stores an error coded data file. Such an error coded data file mayinclude a plurality of sets of encoded data slices, wherein the datafile is dispersed storage error encoded to produce the plurality of setsof encoded data slices. Such identification may be based on one or moreof obtaining (e.g., receiving, extracting from a list) an error codeddata file identifier (ID) associated with the error coded data file, asource name associated with the error coded data file ID, a source namerange, a slice name range, a source name to physical location tablelookup, a retrieve data request message, a store data request message,available sets of DS units, DS unit attributes, and metadata.

The method continues at step 210 where the processing module identifiesa reference entity within the computing system network. Such anidentification may be based on one or more of a reference entity listlookup, a user device to reference entity list lookup, a DS processingunit to reference entity list lookup, a DS processing module toreference entity list lookup, a computing system network topology, and anext reference entity in a reference entity sequence. In addition, theprocessing module may identify a second reference entity within thecomputing system network.

The method continues at step 212 where the processing module determinesfirst data access performance information between the reference entityand a first one of the sets of DS units and determines second dataaccess performance information between the reference entity and a secondone of the sets of DS units for each of the plurality of DSNs. Inaddition, when utilizing a second reference entity, the processingmodule determines third data access performance information between thesecond reference entity and the first one of the sets of DS units anddetermines fourth data access performance information between the secondreference entity and the second one of the sets of DS units for each ofthe plurality of DSNs.

Such a determination of the performance information may include one ormore of determining a likelihood of retrieving a decode threshold numberof encoded data slices of at least a portion of the error coded datafile, determining data retrieval access latency for retrieving thedecode threshold number of encoded data slices, and generating the dataaccess performance information based on the likelihood of retrieving thedecode threshold number of encoded data slices and the data retrievalaccess latency.

Alternatively, such a determination of the performance information mayinclude one or more of determining a likelihood of storing a writethreshold number of encoded data slices of the at least a portion of theerror coded data file, determining data write access latency for storingthe write threshold number of encoded data slices, and generating thedata access performance information based on the likelihood of storingthe write threshold number of encoded data slices and the data writeaccess latency.

The method continues at step 214 for the processing module stores thefirst and second data access performance information for each of theplurality of DSNs to produce system data access performance information.In addition, the processing module stores the third and fourth dataaccess performance information for each of the plurality of DSNs as partof the system data access performance information when utilizing asecond reference entity. In addition, the processing module may updateprevious data access performance information with current data accessperformance information to produce the data access performanceinformation. In addition, the processing module may output the dataaccess performance information to an accessing device such that theaccessing device determines specific data access performance informationbased on the reference entity's data access performance information. Forexample, the processing module outputs the data access performanceinformation on a timed basis. As another example, the processing moduleoutputs the data access performance information in response to arequest.

FIG. 11 B is another flowchart illustrating another example of accessingdata, which includes similar steps to FIG. 7. Such a data access methodmay be utilized in a computing system network that includes a pluralityof dispersed storage networks (DSNs), wherein each of the plurality ofDSNs includes sets of dispersed storage (DS) units, and wherein a set ofthe sets of DS unit stores an error coded data file. The method beginsat step 218 where a processing module (e.g., of a user device) receivesa data access request message (e.g., read, write, delete, list, etc.).The method continues with steps 116 and 124 of FIG. 7 where theprocessing module determines metadata and determines error codeddispersal storage parameters.

The method continues at step 222 where the processing module determinesslice names corresponding to the error coded data file. Such adetermination may be based on one or more of a file name, a fileidentifier (ID), a user device ID, a user ID, a vault ID, a directoryentry, a directory lookup, a source name retrieval, a source namelookup.

The method continues at step 224 where the processing module contains areference entity's data access performance information. Such referenceentity's data access performance information includes, for each of theplurality of DSN first data access performance information between thereference entity and a first one of the sets of DS units and second dataaccess performance information between the reference entity and a secondone of the sets of DS units. Such obtaining of the reference entity'sdata access performance information includes at least one of outputtinga data access performance information request message that identifiesthe reference entity, receiving the reference entity's data accessperformance information, and retrieving the reference entity's dataaccess performance information from one of the plurality of DSNs or apublishing authority. For example, the processing module determines toread the error coded data file, identifies one or more of the pluralityof DSNs that store a copy of the error coded data file and obtain thesethe reference entity's data access performance information for the oneor more of the plurality of DSNs. As another example, the processingmodule determines to write the error coded data file and obtains thereference entity's data access performance information for each of theplurality of DSNs.

The method continues at step 226 where the processing module interpretsthe first and second data access performance information of at least oneof the plurality of DSNs to identify a desired set of DS units withinone of the plurality of DSNs. Such identification may be based on one ormore of the data name, the user ID, metadata, the error coding dispersalstorage parameters, the slice names, the data access performanceinformation, access performance requirements, a comparison of dataaccess performance information associated with a first set of DS unitsto data access performance information associated with a second set ofDS units, and a comparison of data access performance information to theaccess performance requirements. For example, the processing moduleselects a fourth set of DS units as the desired set of DS units when acomparison of data access performance information associated with thefourth set of DS units compares favorably to the access performancerequirements. As another example, the processing module selects a fifthset of DS units as the desired set of DS units when a comparison of dataaccess performance information associated with the fifth set of DS unitscompares favorably to data access performance information associatedwith the fourth set of DS units. The method continues at step 228 wherethe processing module accesses the desired set of DS units regarding theerror coded data file.

FIG. 12 is a flowchart illustrating an example of migrating data, whichinclude similar steps to FIGS. 7 and 9. The method begins with step 234where a processing module determines a previously stored data copy formigration. Such a determination may be based on one or more of whichstep a migration process left off last time, a data copy migration list,whether an amount of elapsed time since a last migration considerationhas exceeded a time threshold, whether an elapsed time since an initialstorage of the data copy has exceeded a time threshold, a requirementschange indicator, a dispersed storage network (DSN) system status changeindicator, a predetermination, a command, and a message. Such a datacopy migration list may include one or more of a user identifier (ID), adata copy name, a data type indicator, a data object hash, a vault ID, adata size indicator, a priority indicator, a security indicator, storagerequirements, an initial storage timestamp, a time stamp correspondingto the last migration consideration, a time threshold, and a performanceindicator.

The method continues with steps 116-126 of FIG. 7 where the processingmodule determines metadata, determines the replication factor,determines a plurality of DSNs, determines DS unit storage sets,determines error coded dispersal storage parameters, and saves the errorcoding dispersal storage parameters utilizing current data copy storagerequirements and a current status and performance level associated withthe plurality of DSNs. The method continues with step 174 of FIG. 9where the processing module retrieves encoded data slices of the datacopy (e.g., to be migrated).

The method continues with step 130 of FIG. 7 where the processing modulesends the data copy to the units of the DS unit storage sets for storagetherein. For example, the processing module sends the data copy to DSunit storage sets, wherein the DS unit storage sets are substantiallythe same as previous DS unit storage sets utilized to previously storethe data copy when one or more of the metadata, replication factor, theplurality of DSNs, the DS unit storage sets, and the error codingdispersal storage parameters are substantially the same as correspondingprevious metadata, replication factor, plurality of DSNs, DS unitstorage sets, and error coding dispersal storage parameters utilized topreviously store the data copy. As another example, the processingmodule sends the data copy to three DS unit storage sets (e.g., areplication factor of 3) when the data copy was originally stored withreplication factor of 2 and a higher level of reliability is currentlyrequired. As yet another example, the processing module sends the datacopy to a single DS unit storage set when the data copy was initiallystored with replication factor of 2 and a lower level of reliability isacceptable.

FIG. 13 is a flowchart illustrating an example of modifying the storageof data. The method begins with step 252 where a processing moduledetermines access performance to copies of dispersed storage encodeddata, wherein the copies of the dispersed storage encoded data arestored in a set of a plurality of dispersed storage networks (DSNs).Such determining of the access performance includes at least one ofdetermining an access timing performance level, determining anavailability performance level, and determining a reliabilityperformance level. Such determining of the access timing performancelevel may be based on one or more of access timing performancehistorical data (e.g., average for a plurality of user devices, averagethe set of DSNs), a query, at least one ping test, at least onedispersed storage network test, and at least one encoded data sliceaccess timing performance test. Such determining of the availabilityperformance level may be based on one or more of availabilityperformance historical data (e.g., DS unit availability, DSNavailability, a number of DS units online, comparing the number of DSunits online to one or more of a decode threshold, a write threshold,and a read threshold) and at least one encoded data slice availabilitytest. Such determining of the reliability performance level may be basedon one or more of reliability performance historical data (e.g., DS unitreliability, DSN reliability, a number of DS units online, comparing thenumber of DS units online to one or more of a decode threshold, a writethreshold, and a read threshold) and at least one encoded data sliceretrieval success test.

The method continues at step 254 where the processing module determinesthat the access performance is not at the desired access performancelevel by comparing actual global data retrieval access information withestimated global data retrieval accesses of the copies of the dispersedstorage encoded data and indicating that the access performance is notat the desired access performance level when the actual global dataretrieval access information compares unfavorably with the estimatedglobal data retrieval accesses. Such estimated global data retrievalaccesses may include a desired access performance level furtherincluding one or more of an access timing storage performance levelgoal, an availability storage performance level goal, and a reliabilitystorage performance level goal.

The method continues at step 256 where the processing module modifiesthe set of the plurality of DSNs based on the access performance and thedesired access performance level to produce a modified set of theplurality of DSNs when the access performance is not at a desired accessperformance level. Such modification of the set of the plurality of DSNsmay include one or more of adding a new DSN, removing a current DSN, andreusing a current DSN. For example, the processing module determinesdifferences between the actual global data retrieval access informationand the estimated global data retrieval accesses of the copies of thedispersed storage encoded data and identifies the new DSN based on thedifferences. As another example, the processing module identifies a DSNof the set of DSNs to remove from the set of DSNs based on differencesbetween the actual global data retrieval access information and theestimated global data retrieval accesses of the copies of the dispersedstorage encoded data. As yet another example, the processing moduleidentifies a remaining DSN of the set of DSNs to reuse based onreliability information of the access performance and desiredreliability of the desired access performance level.

The method continues at step 258 where the processing module determineswhether the new DSN is added. The method branches to step 264 when theprocessing module determines not to add the new DSN. The methodcontinues to step 260 when the processing module determines to add thenew DSN. The method continues at step 260 where the processing moduledetermines error coding dispersal storage parameters based on local dataretrieval accesses allocated to the new DSN for the new DSN of amodified set of the plurality of DSNs. The method continues at step 262where the processing module facilitates the new DSN storing another copyof the dispersed storage encoded data. Such facilitation includes atleast one of retrieving one of the copies from a remaining DSN of theset of DSNs, decoding the one of the copies based on error codingdispersal storage parameters of the remaining DSN to produce the data,encoding the data in accordance with the error coding dispersal storageparameters to produce the other copy, and outputting the other copy tothe new DSN. Alternatively, the facilitation includes determining that aremaining DSN of the set of DSNs utilized the error coding dispersalstorage parameters and coordinating forwarding the other copy from theremaining DSN to the new DSN. As yet another alternative, thefacilitation includes outputting the other copy to at least two DSNs ofthe modified set of the plurality of DSNs, wherein the at least to DSNsincludes the new DSN (e.g., a first portion of a set of encoded dataslices to one DSN and a remaining portion of the set of encoded dataslices to the second DSN).

The method continues at step 264 where the processing module determineswhether to remove the DSN of the set of DSNs to remove. The methodbranches to step 266 when the processing module determines not to removethe DSN of the set of DSNs. The method continues to step 265 when theprocessing module determines to remove the DSN of the set of DSNs. Themethod continues at step 265 where the processing module removes the DSNfrom the set of DSNs. For example, the processing module removes the DSNfrom a list of DSNs then includes a copy of the copies of the dispersedstorage encoded data. Alternatively, or in addition to, the processingmodule deletes a copy of the copies of the dispersed storage encodeddata associated with the DSN of the set of DSNs.

The method continues at step 266 where the processing module determineswhether to reuse the remaining DSN of the set of DSNs to reuse. Themethod branches to step 269 for the method ends when the processingmodule determines not to reuse the remaining DSN of the set of DSNs toreuse. The method continues to step 265 when the processing moduledetermines to reuse the remaining DSN of the set of DSNs to reuse. Themethod continues at step 267 where the processing module determines newerror coding dispersal storage parameters for a remaining DSN based on adifference between the reliability information of the access performanceand the desired reliability of the desired access performance level.

The method continues at step 268 where the processing module facilitatesthe remaining DSN storing an updated copy of the dispersed storageencoded data based on the new error coding dispersal storage parameters.For example, the processing module retrieves a copy (e.g., a pluralityof sets of encoded data slices) of the dispersed storage encoded datafrom the remaining DSN, dispersed storage error decodes the copy toreproduce the data, dispersed storage error encodes the data utilizingthe new error coding dispersal storage parameters to produce the updatedcopy, and stores the updated copy in the remaining DSN. In an instance,the new error coding dispersal storage parameters includes a same decodethreshold number as the error coding dispersal storage parameters and alarger width then a width of the error coding dispersal storageparameters. In such an instance, additional encoded parity slices areadded to the remaining DSN (e.g., to improve retrieval reliability).Alternatively, or in addition to, the processing module outputs theupdated copy to at least two DSNs of the set of DSNs to reuse, whereinthe set of DSNs includes the remaining DSN (e.g., a first portion of aset of encoded data slices to one DSN and a remaining portion of the setof encoded data slices to the second DSN). The method continues to step269 where the method ends.

FIG. 14 A is a flowchart illustrating an example of generating billinginformation. The method begins with step 270 where a processing module(e.g., of a dispersed storage (DS) managing unit) determines dispersedstorage network DSN usage information. Such DSN usage informationincludes one or more of resource use, user activity by user identifier(ID), user activity by vault ID, resource use since a previous update,activity since a last update, amount of storage utilization, number ofdata segments stored, number of storage sequences, number retrievalsequence, and any other information that characterizes use inactivitywithin a corresponding DSN system. Such a determination may be based onone or more of monitoring usage, monitoring activity, historicalactivity records, historical usage records, a query, a vault lookup, amessage, and a command. For example, the processing module determinesthat user 457 affiliated with DSN system 1 has used 1.496 terabytes ofstorage since a last update. As another example, the processing moduledetermines that the vault A40 affiliated with DSN system 2 has performed10,492 retrieval sequences since a last update.

The method continues with step 272 where the processing moduledetermines whether to send the DSN usage information. Such adetermination may be based on one or more of an elapsed time since aprevious update was sent has exceeded a time threshold, a command,receiving a request to send the DSN usage information, a query, apredetermination, an error message, a new transaction indicator, and aDSN system status indicator. For example, the processing moduledetermines to send the DSN usage information when 10 minutes has elapsedsince a previous update was sent and the time threshold is 9 minutes.The method repeats back to step 270 when the processing moduledetermines not to send DSN usage information. The method continues tostep 274 when the processing module determines to send the DSN usageinformation.

The method continues at step 274 where the processing module sends theDSN usage information to one or more of a billing authority, a DSmanaging unit, a DS unit, a DS processing unit, and a storage integrityprocessing unit. For example, the processing module sends the DSN usageinformation to a billing authority that is operably coupled to two ormore DSN systems to resolve billing information between the two or moreDSN systems. For instance, the processing module sends billing amounts(e.g., monetary values) corresponding to the DSN usage information inaccordance with a billing rate to the billing authority. Such a billingauthority may balance credits and debits between two or more DSN systemsas discussed in greater detail with reference to FIG. 14 B.

FIG. 14 B is a flowchart illustrating an example of aggregatingdispersed storage network (DSN) usage information. The method beginswith step 276 where a processing module (e.g., of a billing authority)receives DSN usage information from two or more DSNs. For example, theprocessing module receives DSN 1 usage information from a dispersedstorage (DS) managing unit associated with DSN 1 and the processingmodule receives DSN 2 usage information from a DS managing unitassociated with DSN 2.

The method continues at step 278 where the processing module determineswhether to aggregate the DSN usage information. Such a determination maybe based on one or more of an elapsed time since a previous aggregationhas exceeded an aggregation time threshold, a command, a query, apredetermination, an error message, a new transaction indicator, and aDSN system status indicator. The method repeats back to step 276 whenthe processing module determines that to aggregate the DSN usageinformation. The method continues to step 280 when the processing moduledetermines to aggregate the DSN usage information.

The method continues at step 280 where the processing module aggregatesthe DSN usage information. Such aggregation includes one or more ofsummarizing DSN resource usage by user identifier (ID) and/or vault ID,summarizing DSN activity by user ID and/or vault ID, summarizing DSNresource usage, summarizing DSN activity, converting usage informationinto billing information based on one or more billing rates, tradingusage between different DSN systems, and trading credits and debitsbetween different DSN systems. For example, the processing module evenlytrade 10 units of DSN system 2 usage by user 123 of DSN system 1 for 10units of DSN system 1 usage by user 456 of DSN system 2. As anotherexample, the processing module creates a debit of two units for DSNsystem 1 when there are 8 units of DSN system 2 usage by user 123 of DSNsystem and there are 10 units of DSN system 1 usage by user 456 of DSNsystem 2. Such a unit of use may include an amount of storage per unitof time of one or more of data object storage, data segment storage,data slices of a pillar storage, and a data slice.

The method continues at step 282 where the processing module creates abilling report. Such a billing report indicates one or more of the DSNusage information, billing information, and a net credit and debitbalance by DSN system ID, user ID and/or vault ID. The processing modulemay send the billing report to one or more DS managing units associatedwith one or more DSNs.

FIG. 15 A is another flowchart illustrating another example of storingdata, which include similar steps to FIG. 7. The method begins withsteps 114, 116, and 118 of FIG. 7 where a processing module (e.g.,associated with a dispersed storage network (DSN) that does not includea dispersed storage (DS) unit but rather interfaces to a plurality ofDSN systems that each include at least one DS unit, for instance, aninternet service provider portal) receives a store data request message,determines metadata, and determines a replication factor.

The method continues at step 290 where the processing module determinesother DSN systems, wherein each DSN system of the other DSN systemsincludes at least one DS unit (e.g., where a data copy shall be stored).Such a determination may be based on one or more of attributesassociated with a DSN portal, permissions associated with a useridentifier (ID) associated with the store data request message, thereplication factor, available DSN systems, DSN system attributes, datato be stored, storage requirements, the metadata, a message, and alookup. For example, the processing module determines to store the dataand a data copy of the data in DSN systems 3 and 8 when the processingmodule determines that DSN system attributes of DSN 3 and DSN 8substantially match storage requirements (e.g., closer geographicproximity of DSN systems 3 and 8 to a user device associated with thedata). Note that the processing module may determine to not utilize alocal DSN system associated with the processing module when theprocessing module determines that the local DSN system attributesindicate that there are no DS units (e.g., the processing module isassociated with portal with no associated storage).

The method continues with steps 124, 126, and 128 of FIG. 7 where theprocessing module determines error coding dispersal storage parameters,saves the error coding dispersal storage parameters, and encodes thedata to produce a copy (e.g., at least a plurality of sets of encodeddata slices). The method continues with the step where the processingmodule sends the plurality of sets of encoded data slices and the errorcoding dispersal storage parameters to the other DSNs for storagetherein.

FIG. 15 B is another flowchart illustrating another example ofretrieving data, which include similar steps to FIGS. 7, 9, and 15 A.The method begins with step 162 of FIG. 9 where a processing module(e.g., associated with a dispersed storage network (DSN) that does notinclude a dispersed storage (DS) unit but rather interfaces to aplurality of DSN systems that each include at least one DS unit, forinstance, an internet service provider portal) receives a retrieve datarequest message from a requester (e.g., a user device). The methodcontinues with steps 116, 122, and 124 of FIG. 7 where the processingmodule determines metadata, determines DS unit storage sets, anddetermines error coding dispersal storage parameters. The methodcontinues with step 290 of FIG. 15 A where the processing moduledetermines other DSN systems. For example, the processing moduledetermines DSN identifiers (IDs) of each DSN of the other DSN systemsbased on a file ID associated with the retrieved data request messageand a file ID to DSN system table lookup.

The method continues at step 310 where the processing module selects DSunits of the other DSNs to produce selected DS units. Such a selectionmay be based on one or more of the metadata, retrieval performancerequirements, a DSN performance indicator, a DSN query, a replicationfactor, the DS unit storage sets the error coding dispersal storageparameters, the other DSN systems, DS unit attributes, DS unitavailability information, DS unit reliability information, DS unitaccess cost, and DS unit performance information. For example, theprocessing module selects DS units of the other DSN systems that areclosest to the processing module based on DS unit attributes and aquery. The method continues with steps 174, 176, and 178 of FIG. 9 wherethe processing module retrieves at least a decode threshold number ofencoded data slices of each of a plurality of sets of encoded dataslices corresponding to the data from the selected DS units, dispersedstorage error decodes the at least the decode threshold number ofencoded data slices of each of the plurality of sets encoded data slicesto the produce data in accordance with the error coding dispersalstorage parameters, and sends the data object to the requester.

FIG. 16 A is a flowchart illustrating an example of assigning a newvault. Such a new vault may be associated with one or more dispersedstorage networks (DSNs). The method begins with step 318 where aprocessing module (e.g., of a dispersed storage (DS) managing unit)receives a new vault assignment request from one of a user device,another DS managing unit, and another DSN system. Such a new vaultassignment request may include one or more of a user identifier (ID), auser device ID, a vault ID, a group ID, and a naming domain. Such anaming domain refers to utilization of the new vault including global,regional, sub-regional, local, and sub-local.

The method continues at step 319 where the processing module determinesa naming domain based on one or more of information interpreted from thenew vault assignment request, a user ID, a naming domain table lookup, avault lookup, a vault list, a message, and a command. The method endswith step 320 where the processing module assigns local namespace to anew vault when the processing module determines that the naming domainis local. Such local namespace may include a range of source namesand/or slice name addresses that are uniquely utilized in one or moreDSNs. Such similar namespace may be assigned for use in two or more DSNsenabling use of the namespace range localized within each of the two ormore DSNs. The method branches to step 321 when the processing moduledetermines that the naming domain is not local (e.g., global, regional,sub-regional).

The method continues at step 321 where the processing module forwardsthe new vault assignment request to a naming authority. The methodcontinues at step 322 where the processing module receives non-local newvault assignment information (e.g., from the naming authority inresponse to forwarding the new vault request). Such non-local new vaultassignment information may include one or more of vault ID information,user ID information, source name range information, and slice name rangeinformation. The method continues at step 323 where the processingmodule stores the new vault assignment information for subsequentutilization by a DSN operationally affiliated with the processing module(e.g., a DS managing unit affiliated with the DSN).

FIG. 16 B is another flowchart illustrating another example of assigninga new vault, which include similar steps to FIG. 16 A. The method beginswith steps 318 and of FIG. 16 A where a processing module (e.g., of anaming authority) receives a new vault assignment request and determinesa naming domain. For example, the processing module determines that thenaming domain is global when the new vault assignment request includes arequest for a global naming domain.

The method continues at step 326 where the processing module assignsnamespace to a new vault. Note that the namespace may include a range ofsource name and/or slice name addresses that are utilized across two ormore dispersed storage networks (DSNs). For example, the processingmodule assigns namespace that is shared amongst two or more DSNs whenthe naming domain is global. Note that such namespace assignment mayfurther include assignment of one or more new user IDs and/or one ormore new vault IDs. The method continues with step 323 of FIG. 16 Awhere the processing module stores new vault assignment information toenable subsequent operation of two or more DSNs. The method continues atstep 328 where the processing module sends the non-local new vaultassignment information to DS managing unit(s) of affected DSNs.

FIG. 16 C is a flowchart illustrating an example of accessing adispersed storage network. A method begins with step 329 where aprocessing module receives a dispersed storage network (DSN) accessrequest. Such an access request may include one or more of a useridentifier (ID), a user device ID, a vault ID, a DSN ID, a source name,a file name, a file ID, a data type indicator, a priority indicator, aperformance indicator, a security indicator, and a reliabilityindicator.

The method continues at step 330 where the processing module determineswhether the DSN access request is associated with a local DSN vault or aglobal DSN vault, wherein the local DSN vault is contained within a DSNof a plurality of DSNs (e.g., local DSN vault includes a namespaceaddress range utilized within at least one DSN and potentially reusedwithin at least one other DSN) and the global DSN vault is containedwithin at least some of the plurality of DSNs (e.g., global DSN vaultincludes a namespace address range utilized across two or more DSNs).Such determining includes at least one of interpreting a requesteridentifier of the DSN access request, interpreting a vault identifier ofthe DSN access request, interpreting a data type of the DSN accessrequest, accessing a table look-up, interpreting a local or global DSNidentifier within the DSN access request (e.g., a flag), and querying anaming authority. For example, the processing module determines that theDSN access request is associated with the global DSN vault when thevault ID of the DSN access request is associated with the global DSNvault. As another example, the processing module determines that the DSNaccess request is associated with the global DSN vault based on a queryresponse from the naming authority.

The method branches to step 331 when the processing module determinesthat the DSN access request is associated with the local DSN vault. Themethod continues to step 331 when the processing module determines thatthe DSN access request is associated with the global DSN vault. Themethod continues at step 331 where the processing module determineswhether the DSN access request includes a vault assignment request whenthe processing module determines that the DSN access request isassociated with the global DSN vault. Such a vault assignment requestincludes at least one of a user ID, a user device ID, a group ID, and arequested naming domain (e.g., global, local, regional, sub-regional,sub-local). Such a determination may be based on one or more ofinterpreting the vault assignment request from the DSN access request,determining that the DSN access request is associated with a vaultidentifier that has not been assigned, a message, and an errorindicator.

The method continues at step 332 where the processing module sends thevault assignment request to a naming authority. The method continues atstep 333 where the processing module receives a global vault assignmentresponse that identifies a primary DSN (e.g., associated with the globalDSN vault). The method continues at step 334 where the processing moduleprocesses vault assignment information from a global vault assignmentresponse by one or more of extracting the vault assignment informationfrom the global vault assignment response, storing the vault assignmentinformation, and sending the vault assignment information to a sender ofthe DSN access request.

The method continues at step 335 where the processing module identifiesa primary DSN of the plurality of DSNs. Such identifying includes atleast one of interpreting a requester identifier of the DSN accessrequest, interpreting a global vault identifier of the DSN accessrequest, interpreting a data type of the DSN access request, accessing atable look-up, interpreting a global DSN identifier within the DSNaccess request, and querying a naming authority. The method continues atstep 336 where the processing module facilitates processing of the DSNaccess request by the primary DSN. Such facilitating includesidentifying, by a first DSN of the plurality of DSNs, the first DSN asthe primary DSN, processing, by the first DSN, the DSN access request toproduce a DSN access response, and sending the DSN access response to asender of the DSN access request. Alternatively, the facilitatingincludes identifying, by a first DSN of the plurality of DSNs, a secondDSN of the plurality of DSNs as the primary DSN and forwarding the DSNaccess request to the second DSN.

The method continues at step 331 where the processing module determineswhether the DSN access request includes the vault assignment requestwhen the DSN access request is associated with the local DSN vault. Themethod branches to step 338 when the processing module determines thatthe DSN access request does not include the vault assignment request.The method continues to step 337 when the processing module determinesthat the DSN access request includes the vault assignment request. Themethod continues at step 337 where the processing module creates thelocal vault (e.g., assigns a new local vault identifier to a user of therequest, wherein the new local vault identifier may be reused in one ormore other DSNs). The method continues at step 338 where the processingmodule processes the DSN access request to produce a DSN access responsewhen the DSN access request does not include the vault assignmentrequest. For example, the processing module facilitates storing anencoded data slice in the local DSN vault and generates a write responsemessage as the DSN access response when the DSN access request includesa write request. As another example, the processing module facilitatesretrieving an encoded data slice from the local DSN vault and generatesa read response message that includes the encoded data slice as the DSNaccess response when the DSN access request includes a read request. Themethod continues at step 339 where the processing module sends the DSNaccess response to a sender of the DSN access request.

FIG. 17 A is a flowchart illustrating an example of acquiring securityinformation. The method begins with step 340 where a processing module(e.g., of a dispersed storage (DS) managing unit) outputs a dispersedstorage network (DSN) registration request message to a securityauthority. For example, the processing module determines to send the DSNregistration request message based on at least one of when an affiliatedDS managing unit is brought online, when the DS managing unit reboots,and when a previous signed certificate expires. Such a DS managing unitmay serve as a local DSN certificate authority (CA) with respect toelements (e.g., a user device, a DS processing unit, other DS managingunits, a storage integrity processing unit, and a DS unit) of a localDSN and may serve as an intermediate CA with respect to a root CA (e.g.,a security authority), wherein the root CA is associated with aplurality of DSNs that includes the local DSN. Such a DSN registrationrequest message may include one or more of a DSN identifier (ID), a DSmanaging unit ID, an affiliated user device ID, DSN storage capacityparameters, DSN system status, DSN storage availability parameters, DSNcontrolling authority contact information, and any other information tofacilitate utilization of DSN system resources. Such outputting of theDSN registration request message includes sending the DSN registrationrequest message to one or more of a security authority, a managementauthority, a naming authority, a billing authority, and the publishingauthority. For example, the processing module sends the DSN registrationrequest message to the security authority when the processing moduledetermines that local DSN has been initialized but has not registeredwith the security authority.

The method continues at step 342 where the processing module receives aDSN registration response message. Such a DSN registration responsemessage includes a local DSN certificate authority universal uniqueidentifier (UUID). Such a UUID uniquely identifies each system elementand in an instance is 16 bytes in length. The method continues at step344 where the processing module generates and saves a DSN CA public keyand a paired local DSN CA private key such that information encryptedwith the private key may be decrypted with the public key andinformation encrypted with the public key may be decrypted with theprivate key. For example, only the processing module utilizes theprivate key to encrypt or decrypt messages when the processing modulefunctions as the local DSN CA and any other system element utilizes thepublic key to encrypt or decrypt messages to and from the local DSN CA.

The method continues at step 346 where the processing module generates alocal DSN CA certificate signing request (CSR). Such a request mayinclude one or more of the local DSN CA UUID, the local DSN CA publickey, and a local DSN CA signature. Such a local DSN CA signature may begenerated by encrypting a hash digest of the request content utilizingthe local DSN CA private key. The method continues at step 348 where theprocessing module sends the local DSN CA CSR to the security authority.

The method continues at step 350 where the processing module receives alocal DSN CA signed certificate signed by security authority (e.g., aroot CA) from the security authority. The processing module may validatethe signed certificate by comparing a decrypted signature of the signedcertificate, utilizing a root CA public key included in the certificate,to a hash digest of the content of the certificate. Next, the processingmodule determines that the certificate is valid when the comparison isfavorable (e.g., the same). Next, the processing module saves the rootCA signed local DSN CA certificate when the processing module determinesthat the certificate is valid.

The local DSN DS managing unit may serve as an intermediary for theoverall root CA of the security authority such that the managing unitmay register and issue signed certificates to elements of the local DSNoperating within the local DSN and requesting access to system elementswithin another DSN of the plurality of DSNs.

FIG. 17 B is a flowchart illustrating an example of assigning securityinformation. The method begins with step 352 where a processing module(e.g., of a security authority) receives a dispersed storage network(DSN) registration request from a DSN (e.g., from a dispersed storage(DS) managing unit acting as a certificate authority of the DSN). Such asecurity authority may be associated with a plurality of DSNs and mayserve as at least one of a root certificate authority (CA) and aregistration authority with respect to the DSN of the plurality of DSNs.Next, the processing module processing module validates the DSNregistration request by comparing DSN information of the DSNregistration request to saved DSN information from a previousregistration process to authenticate the DSN registration request. Forexample, the processing module determines that the comparison isfavorable when identity information contained in the DSN information issubstantially the same as identity information in the saved DSNinformation.

The method continues at step 354 where the processing module generates alocal DSN CA universal unique identifier (UUID) and generates billinginformation when the processing module determines that the DSNregistration request message is valid. Such billing information mayinclude one or more of the local DSN CA UUID, the DSN information, DSNcontact information, DSN user device information, and billing rates. Theprocessing module may send the billing information to one or more of amanagement authority, a naming authority, a billing authority, and apublishing authority. The method continues at step 356 where theprocessing module sends a registration response to the local DSN CA thatincludes the DSN CA UUID and an authorization code.

The method continues with step 358 where the processing module receivesa DSN certificate signing request (CSR) from the local DSN CA. Themethod continues at step 360 where the processing module validates theCSR. Such validating includes comparing a hash digest of the CSR contentto a decrypted local DSN CA signature utilizing the local DSN CA publickey. The processing module validates the CSR when the comparison isfavorable (e.g., substantially the same). Next, the processing modulesaves the local DSN CA public key received in the CSR.

The method continues at step 362 where the processing module generates asigned local DSN CA certificate signed by the security authority whenthe processing module validates the CSR. Such a root CA signed local DSNCA certificate may include one or more of the local DSN CA certificatesigning request, a root CA UUID, a root CA public key, and a root CAsignature. Such a root CA signature may be generated by encrypting ahash digest of the certificate content utilizing a root CA private key.The method continues at step 364 where the processing module sends theroot CA signed local DSN CA certificate to the local DSN CA. Such amethod verifies that the local DSN CA can issue signed certificates toDSN elements on behalf of the root CA such that the DSN elements maysubsequently access DSN elements of the plurality of DSNs.

FIG. 18 A is a flowchart illustrating another example of acquiringsecurity information. The method begins with step 368 where a processingmodule (e.g., of a user device) outputs a registration request messagethat includes requesting access to a local dispersed storage network(DSN) and requesting access to a global DSN, wherein the global DSNincludes a plurality of DSNs and the local DSN is one of the pluralityof DSNs. Such a registration request message includes at least one of arequester identifier (ID), a DSN ID, a dispersed storage (DS) managingunit ID, a DS processing unit ID, a user device ID, a DSN storagecapacity indicator, a DSN status indicator, a DSN storage availabilityindicator, and authority contact information. Such outputting of theregistration request message includes sending the registration requestmessage to at least one of a local DSN registration authority, a globalDSN registration authority, a certificate authority (CA), a securityauthority, a management authority, a naming authority, a billingauthority, and a publishing authority.

The method continues at step 370 where the processing module receives aregistration response message that includes a global universal uniqueidentifier (UUID) and a local UUID. The method continues at step 372where the processing module generates a global public-private key pairand a local public-private key pair. For example, the processing modulegenerates the global public-private key pair and generates the localpublic-private key pair such that the local public-private key pair issubstantially the same as the global public-private key pair. Next, theprocessing module saves the global public-private key pair and the localpublic-private key pair.

The method continues at step 374 where the processing module generates aglobal certificate signing request (CSR) based on the global UUID and aprivate key of the global public-private key pair. Such a global CSRincludes at least one of a global authorization code, the global UUID, aglobal public key of the global public-private key pair, and a globalsignature, wherein the global signature includes an encrypted hash ofthe global CSR utilizing a private key of the global public-private keypair. At step 374, the processing module generates a local CSR based onthe local UUID and a private key of the local public-private key pair.Such a local CSR includes at least one of a local authorization code,the local UUID, a local public key of the local public-private key pair,and a local signature, wherein the local signature includes an encryptedhash of the local CSR utilizing a private key of the localpublic-private key pair.

The method continues at step 376 where the processing module sends theglobal and local CSRs to a certificate authority (CA) (e.g., a securityauthority associated with the plurality of DSNs). Alternatively, theprocessing module sends the global CSR to a global CA and the local CSRto a local CA. The method continues at step 378 where the processingmodule receives a signed global certificate and a signed localcertificate. Next, the processing module saves the signed globalcertificate and the signed local certificate and to utilize thecertificates in subsequent DSN access requests.

FIG. 18 B is a flowchart illustrating another example of assigningsecurity information. The method begins with step 380 where a processingmodule receives a registration request from a valid requesting entity(e.g., the processing module may validate the requesting entity byfavorably comparing a requester identifier (ID) with a stored requesterID from a previous registration process). The method continues at step382 where the processing module determines whether the registrationrequest includes requesting registration to a global dispersed storagenetwork (DSN) that includes a plurality of DSNs. Such a determinationmay be based on one or more of the requester ID, a received DSN ID, atable lookup, and a message. At step 382, the processing moduledetermines whether the valid requesting entity has a local universallyunique identifier (UUID) of a home DSN of the plurality of DSNs when theregistration request is requesting registration to the global DSN. Sucha determination may be based on one or more of a list of UUIDsassociated with the home DSN, a lookup, and a message. Next, theprocessing module generates a global UUID when the registration requestincludes requesting registration to the global DSN and when the validrequesting entity has the local UUID. The processing module generatesthe local UUID and the global UUID when the valid requesting entity doesnot have the local UUID when the registration request includesrequesting registration to the global DSN. In addition, the processingmodule may facilitate initialization of billing information for thevalid requesting entity when the valid requesting entity does not havethe local UUID.

The method continues at step 384 where the processing module sends, tothe valid requesting entity, a registration response that includes oneor more of the local UUID (e.g., newly generated or retrieved from aprevious generation sequence) and a local authorization code that isassociated with the local UUID, and the global UUID and a globalauthorization code that is associated with the global UUID. The methodcontinues at step 386 where the processing module receives a globalcertificate signing request (CSR) from the valid requesting entity. Themethod continues at step 388 where the processing module validates theglobal CSR by at least one of a favorable comparison of a receivedauthorization code of the global CSR with a stored authorization codeassociated with the global UUID and a favorable comparison of a hash ofthe global CSR with a decrypted signature of the global CSR utilizing apublic key of the global CSR.

The method continues at step 390 where the processing module generates aglobal signed certificate when the global CSR is valid. Such a globalsigned certificate includes at least one of the global CSR, a globalcertificate authority (CA) UUID, a CA signature, and a CA public key ofa public-private key pair. The processing module may generate the CAsignature by at least one of hashing the global signed certificate,encrypting the global signed certificate utilizing a CA private key ofthe public-private key pair, hashing and encrypting the global signedcertificate utilizing the CA private key of the public-private key pair,and retrieving the CA signature from another CA (e.g., from a securityauthority CA). The method continues at step 392 where the processingmodule sends the global signed certificate to the valid requestingentity. Alternatively, the processing module receives a local CSR fromthe valid requesting entity, generates a local signed certificate, sendsthe local signed certificate to the valid requesting entity when thelocal CSR is valid and when the valid requesting entity does not havethe local UUID. Such a method enables the processing module (e.g., ofthe user device) to subsequently access different DSN elements of theplurality of DSNs by presenting the signed certificate. Such a method toaccess different DSN elements is discussed in greater detail withreference to FIGS. 19 A and 19 B.

FIG. 19 A is a flowchart illustrating an example of requesting access toa dispersed storage network (DSN). The method begins with step 396 wherea processing module (e.g., of a user device) receives a data accessrequest. Such an access may include one or more of a write request, aread request, a delete request, a list request, etc. Such data may bestored as one or more copies in one or more DSNs. The method continuesat step 398 where the processing module determines whether the dataaccess request is requesting access to data stored in a plurality ofDSNs (e.g., in just one or two or more DSNs). Such determining includesone or more of determining whether access to the plurality of DSNs isestablished, establishing access to the plurality of DSNs (e.g.,registering and obtaining signed certificates) when the access to theplurality of DSNs is not established, and accessing a DSN look up tablebased on the data access request when the access to the plurality ofDSNs is established. For example, the processing module accesses the DSNlookup table to retrieve the plurality of DSNs when the data accessrequest is a read request. As another example, the processing moduleaccesses the DSN lookup table to determine (e.g., based on storagerequirements and DSN attributes) the plurality of DSNs when the dataaccess request is a write request.

The method branches to step 408 when the processing module determinesthat the data access request is not requesting access to data stored inthe plurality of DSNs (e.g., the request is to access data in just oneDSN). The method continues to step 400 when the processing moduledetermines that the data access request is requesting access to datastored in the plurality of DSNs.

The method continues at step 400 where the processing module determineswhether one of the plurality of DSNs is a home DSN to a requestingentity. Such a determination may be based on one or more of a useridentifier (ID), DSN IDs associated with the plurality of DSNs, a userID affiliation to DSN ID table lookup, a DSN ID from the data accessrequest, and a message. For example, the processing module determinesthat one of the plurality of DSNs is the home DSN when the plurality ofDSNs includes DSN 3, DSN 5, and DSN 7 and a DSN ID table lookupindicates that DSN 5 is a home DSN for the requesting entity (e.g., ofan associated user device). The method branches to step 404 when theprocessing module determines that one of the plurality of DSNs is notthe home DSN to the requesting entity. The method continues to step 402when the processing module determines that one of the plurality of DSNsis the home DSN to the requesting entity. The method continues at step402 where the processing module utilizes a local signed certificate toaccess one or more dispersed storage (DS) units of the home DSN when theplurality of DSNs includes the home DSN.

The method continues at step 404 where the processing module validates aglobal signed certificate with one or more DS units of a non-home DSN ofthe plurality of DSNs to produce a valid global signed certificate. Suchvalidating of the global signed certificate with the one or more DSunits of the non-home DSN includes at least one of validating the globalsigned certificate with each of the one or more DS units of the non-homeDSN of the plurality of DSNs to produce a set of valid global signedcertificates and validating the global signed certificate with a proxyunit (e.g., a DS unit or other unit within the plurality of DSNs) of theone or more DS units of the non-home DSN of the plurality of DSNs toproduce the valid global signed certificate. Alternatively, suchvalidating of the global signed certificate with the one or more DSunits of the non-home DSN includes obtaining the global signedcertificate from a local memory or from a certificate authority, sendingthe global signed certificate to the one or more DS units of thenon-home DSN and receiving a challenge message from the one or more DSunits of the non-home DSN, generating a challenge response message inaccordance with the challenge message and based on the global signedcertificate, sending the challenge response message to the one or moreDS units of the non-home DSN, and receiving validation (e.g., avalidation message and/or an access response) from the one or more DSunits of the non-home DSN. The method continues at step 406 where theprocessing module utilizes the valid signed certificate to access theone or more DS units of the non-home DSN.

The method continues at step 408 where the processing module determineswhether the one of the plurality of DSNs is the home DSN or the non-homeDSN when the data access request is requesting access to data stored inone of the plurality of DSNs. The method branches to step 410 when theprocessing module determines that the one DSN is the home DSN. Themethod continues to step 402 when the processing module determines thatthe one DSN is the non-home DSN. The method continues at step 402 wherethe processing module accesses one or more DS units of the home DSNutilizing the local signed certificate.

The method continues at step 410 where the processing module validates aglobal signed certificate with a set of DS units of a non-home DSN ofthe plurality of DSNs to produce the valid global signed certificatewhen the one of the plurality of DSNs is the non-home DSN. The methodcontinues at step 412 where the processing module utilizes the validglobal signed certificate to access the set of DS units of the non-homeDSN.

FIG. 19 B is a flowchart illustrating an example of processing adispersed storage network (DSN) access request. The method begins withstep 414 where a processing module (e.g., of a dispersed storage (DS)unit) receives, from a requesting entity (e.g., a user device), anaccess request that includes a signed certificate. The method continuesat step 416 with the processing module determines whether the requestingentity is affiliated with a home dispersed storage network (DSN) (e.g.,a DSN receiving the access request). Such a determination may be basedon one or more of a requesting entity identifier (ID), a received homeDSN ID, a predetermined home DSN ID, a requesting entity ID to home DSNID table lookup, a query, and a message. For example, the processingmodule determines that the requesting entity is affiliated with the homeDSN when a requesting entity ID to home DSN ID table lookup based in thecase that the home DSN ID is 5 and the predetermined home DSN ID is 5(e.g., a DSN associated with the processing module).

The method branches to step 418 when the processing module determinesthat the requesting entity is not affiliated with the home DSN. Themethod continues to step 417 when the processing module determines thatthe requesting entity is affiliated with the home DSN. The methodcontinues at step 417 where the processing module processes the accessrequest as a local DSN access request. For example, the processingmodule authenticates the signed certificate as a local DSN signedcertificate and executes the access request when the signed certificateis favorably authenticated.

The method continues at step 418 where the processing module validatesthe signed certificate when the requesting entity is not affiliated withthe home DSN, wherein such validation includes authenticating the signedcertificate in accordance with an authenticating function. Such anauthenticating function includes determining whether the signedcertificate is authentic based on at least one of sending the signedcertificate to an authenticating authority entity (e.g., to a securityauthority) and determining that a hash of at least a portion (e.g., acertificate) of the signed certificate compares favorably to a decryptedcorresponding portion (e.g., a signature) of the signed certificateutilizing a public key associated with the requesting entity. The methodbranches to step 422 when the processing module determines that thesigned certificate is authentic. The method continues to step 420 whenthe processing module determines that the signed certificate is notauthentic. The method continues at step 420 where the processing modulerejects the access request. Such rejecting includes one or more ofsending a reject message to the requesting entity and sending an errormessage to a dispersed storage managing unit.

The method continues at step 422 where the processing module continuesto validate the signed certificate including generating a challengemessage based on the access request when the signed certificate isauthenticated. Such generating of the challenge message includes atleast one of generating a message to include a secret (e.g., a randomnumber, a predetermined character, a predetermined number), generating achallenge instruction that includes an instruction to return a signatureof the message using a private key associated with the requestingentity, encrypting the secret utilizing a public key associated with therequesting entity to produce an encrypted secret for inclusion in themessage, and generating the challenge instruction to include aninstruction to return a decrypted secret using the private key.

The method continues at step 424 with a processing module outputs thechallenge message to the requesting entity. The method continues at step426 where the processing module receives a challenge response messagefrom the requesting entity and determines whether the challenge responsemessage compares favorably to an expected response. Such determiningwhether the challenge response message compares favorably to theexpected response includes at least one of determining that thesignature of the message using the private key is valid based on thepublic key (e.g., a hash of the message is substantially the same as adecrypted signature utilizing the public key of the requesting entity)and determining that the decrypted secret compares favorably to thesecret. The method continues at step 428 where the processing moduleexecutes the access request when the challenge response message comparesfavorably to the expected response.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “operably coupled to”, “coupled to”, and/or “coupling” includesdirect coupling between items and/or indirect coupling between items viaan intervening item (e.g., an item includes, but is not limited to, acomponent, an element, a circuit, and/or a module) where, for indirectcoupling, the intervening item does not modify the information of asignal but may adjust its current level, voltage level, and/or powerlevel. As may further be used herein, inferred coupling (i.e., where oneelement is coupled to another element by inference) includes direct andindirect coupling between two items in the same manner as “coupled to”.As may even further be used herein, the term “operable to” or “operablycoupled to” indicates that an item includes one or more of powerconnections, input(s), output(s), etc., to perform, when activated, oneor more its corresponding functions and may further include inferredcoupling to one or more other items. As may still further be usedherein, the term “associated with”, includes direct and/or indirectcoupling of separate items and/or one item being embedded within anotheritem. As may be used herein, the term “compares favorably”, indicatesthat a comparison between two or more items, signals, etc., provides adesired relationship. For example, when the desired relationship is thatsignal 1 has a greater magnitude than signal 2, a favorable comparisonmay be achieved when the magnitude of signal 1 is greater than that ofsignal 2 or when the magnitude of signal 2 is less than that of signal1.

While the transistors in the above described figure(s) is/are shown asfield effect transistors (FETs), as one of ordinary skill in the artwill appreciate, the transistors may be implemented using any type oftransistor structure including, but not limited to, bipolar, metal oxidesemiconductor field effect transistors (MOSFET), N-well transistors,P-well transistors, enhancement mode, depletion mode, and zero voltagethreshold (VT) transistors.

The present invention has also been described above with the aid ofmethod steps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention.

The present invention has been described, at least in part, in terms ofone or more embodiments. An embodiment of the present invention is usedherein to illustrate the present invention, an aspect thereof, a featurethereof, a concept thereof, and/or an example thereof. A physicalembodiment of an apparatus, an article of manufacture, a machine, and/orof a process that embodies the present invention may include one or moreof the aspects, features, concepts, examples, etc. described withreference to one or more of the embodiments discussed herein. Further,from figure to figure, the embodiments may incorporate the same orsimilarly named functions, steps, modules, etc. that may use the same ordifferent reference numbers and, as such, the functions, steps, modules,etc. may be the same or similar functions, steps, modules, etc. ordifferent ones.

The present invention has been described above with the aid offunctional building blocks illustrating the performance of certainsignificant functions. The boundaries of these functional buildingblocks have been arbitrarily defined for convenience of description.Alternate boundaries could be defined as long as the certain significantfunctions are appropriately performed. Similarly, flow diagram blocksmay also have been arbitrarily defined herein to illustrate certainsignificant functionality. To the extent used, the flow diagram blockboundaries and sequence could have been defined otherwise and stillperform the certain significant functionality. Such alternatedefinitions of both functional building blocks and flow diagram blocksand sequences are thus within the scope and spirit of the claimedinvention. One of average skill in the art will also recognize that thefunctional building blocks, and other illustrative blocks, modules andcomponents herein, can be implemented as illustrated or by discretecomponents, application specific integrated circuits, processorsexecuting appropriate software and the like or any combination thereof.

What is claimed is:
 1. A method comprises: for each of a plurality ofdispersed storage networks (DSNs) in a computing system network,identifying sets of dispersed storage (DS) units, wherein a set of thesets of DS unit stores an error coded data file; identifying a referenceentity within the computing system network; for each of the plurality ofDSNs: determining first data access performance information between thereference entity and a first one of the sets of DS units; anddetermining second data access performance information between thereference entity and a second one of the sets of DS units, whereindetermining each of the first and second data access performanceinformation includes: determining a likelihood of retrieving a decodethreshold number of encoded data slices of at least a portion of theerror coded data file; determining data retrieval access latency forretrieving the decode threshold number of encoded data slices; andgenerating the data access performance information based on thelikelihood of retrieving the decode threshold number of encoded dataslices and the data retrieval access latency; and storing the first andsecond data access performance information for each of the plurality ofDSNs to produce system data access performance information.
 2. Themethod of claim 1 further comprises: identifying a second referenceentity within the computing system network; for each of the plurality ofDSNs: determining third data access performance information between thesecond reference entity and the first one of the sets of DS units; anddetermining fourth data access performance information between thesecond reference entity and the second one of the sets of DS units; andstoring the third and fourth data access performance information foreach of the plurality of DSNs as part of the system data accessperformance information.
 3. The method of claim 1, wherein determiningthe data access performance information comprises: determining alikelihood of storing a write threshold number of encoded data slices ofthe at least a portion of the error coded data file; determining datawrite access latency for storing the write threshold number of encodeddata slices; and generating the data access performance informationbased on the likelihood of storing the write threshold number of encodeddata slices and the data write access latency.
 4. The method of claim 1further comprises: updating previous data access performance informationwith current data access performance information to produce the dataaccess performance information.
 5. The method of claim 1 furthercomprises: outputting the data access performance information to anaccessing device such that the accessing device determines specific dataaccess performance information based on the reference entity's dataaccess performance information.
 6. A computer comprises: an interface; amemory; and a processing module operable to: for each of a plurality ofdispersed storage networks (DSNs) in a computing system network,identify sets of dispersed storage (DS) units, wherein a set of the setsof DS unit stores an error coded data file; identify a reference entitywithin the computing system network; for each of the plurality of DSNs:determine first data access performance information between thereference entity and a first one of the sets of DS units; and determinesecond data access performance information between the reference entityand a second one of the sets of DS units, wherein the processing modulefurther functions to determine each of the first and second data accessperformance information by: determining a likelihood of retrieving adecode threshold number of encoded data slices of at least a portion ofthe error coded data file; determining data retrieval access latency forretrieving the decode threshold number of encoded data slices; andgenerating the data access performance information based on thelikelihood of retrieving the decode threshold number of encoded dataslices and the data retrieval access latency; and store, in the memory,the first and second data access performance information for each of theplurality of DSNs to produce system data access performance information.7. The computer of claim 6, wherein the processing module furtherfunctions to: identify a second reference entity within the computingsystem network; for each of the plurality of DSNs: determine third dataaccess performance information between the second reference entity andthe first one of the sets of DS units; and determine fourth data accessperformance information between the second reference entity and thesecond one of the sets of DS units; and store, in the memory, the thirdand fourth data access performance information for each of the pluralityof DSNs as part of the system data access performance information. 8.The computer of claim 6, wherein the processing module further functionsto determine the data access performance information by: determining alikelihood of storing a write threshold number of encoded data slices ofthe at least a portion of the error coded data file; determining datawrite access latency for storing the write threshold number of encodeddata slices; and generating the data access performance informationbased on the likelihood of storing the write threshold number of encodeddata slices and the data write access latency.
 9. The computer of claim6, wherein the processing module further functions to: update, in thememory, previous data access performance information with current dataaccess performance information to produce the data access performanceinformation.
 10. The computer of claim 6, wherein the processing modulefurther functions to: output, via the interface, the data accessperformance information to an accessing device such that the accessingdevice determines specific data access performance information based onthe reference entity's data access performance information.